当包含selected.css时，选择的插件不起作用

Question

我选择了简单的选择，但是当我包含chosen.css时我遇到了问题 我使用示例中的代码：

<select data-placeholder="Choose a Country..." class="chosen-select" style="width:350px;" tabindex="2">
                        <option value="United States">United States</option>
                        <option value="United Kingdom">United Kingdom</option>
                        <option value="Afghanistan">Afghanistan</option>
                        <option value="Aland Islands">Aland Islands</option>
                        <option value="Albania">Albania</option>
                        <option value="Algeria">Algeria</option>
                        <option value="American Samoa">American Samoa</option>
                        <option value="Andorra">Andorra</option>
                        <option value="Angola">Angola</option>
                        <option value="Anguilla">Anguilla</option>
                        <option value="Antarctica">Antarctica</option>
                        <option value="Antigua and Barbuda">Antigua and Barbuda</option>
                        <option value="Denmark">Denmark</option>
                        <option value="Djibouti">Djibouti</option>
                        <option value="Dominica">Dominica</option>
                        <option value="Dominican Republic">Dominican Republic</option>
                        <option value="Ecuador">Ecuador</option>
                        <option value="Egypt">Egypt</option>
                        <option value="El Salvador">El Salvador</option>
                        <option value="Equatorial Guinea">Equatorial Guinea</option>
                        <option value="Eritrea">Eritrea</option>
                        <option value="Estonia">Estonia</option>
                        <option value="Ethiopia">Ethiopia</option>
                        <option value="Falkland Islands (Malvinas)">Falkland Islands (Malvinas)</option>
                        <option value="Faroe Islands">Faroe Islands</option>
                        <option value="Fiji">Fiji</option>
                        <option value="Finland">Finland</option>
                        <option value="France">France</option>
                        <option value="French Guiana">French Guiana</option>
                        <option value="French Polynesia">French Polynesia</option>
                        <option value="French Southern Territories">French Southern Territories</option>
                        <option value="Gabon">Gabon</option>
                        <option value="Gambia">Gambia</option>
                        <option value="Georgia">Georgia</option>
                        <option value="Germany">Germany</option>
                        <option value="Ghana">Ghana</option>
                        <option value="Gibraltar">Gibraltar</option>
                        <option value="Greece">Greece</option>
                        <option value="Greenland">Greenland</option>
                        <option value="Grenada">Grenada</option>
                        <option value="Guadeloupe">Guadeloupe</option>
                        <option value="Guam">Guam</option>
                        <option value="Guatemala">Guatemala</option>
                        <option value="Guernsey">Guernsey</option>
                        <option value="Guinea">Guinea</option>
                        <option value="Guinea-bissau">Guinea-bissau</option>
                        <option value="Guyana">Guyana</option>
                        <option value="Haiti">Haiti</option>
                        <option value="Heard Island and Mcdonald Islands">Heard Island and Mcdonald Islands</option>
                        <option value="Holy See (Vatican City State)">Holy See (Vatican City State)</option>
                        <option value="Iraq">Iraq</option>
                        <option value="Ireland">Ireland</option>
                        <option value="Isle of Man">Isle of Man</option>
                        <option value="Israel">Israel</option>
                        <option value="Italy">Italy</option>
                        <option value="Jamaica">Jamaica</option>
                        <option value="Japan">Japan</option>
                        <option value="Jersey">Jersey</option>
                        <option value="Jordan">Jordan</option>
                        <option value="Kazakhstan">Kazakhstan</option>
                        <option value="Kenya">Kenya</option>
                        <option value="Kiribati">Kiribati</option>
                        <option value="Korea, Democratic People&apos;s Republic of">Korea, Democratic People's Republic of</option>
                        <option value="Korea, Republic of">Korea, Republic of</option>
                        <option value="Kuwait">Kuwait</option>
                        <option value="Kyrgyzstan">Kyrgyzstan</option>
                        <option value="Lao People&apos;s Democratic Republic">Lao People's Democratic Republic</option>
                        <option value="Latvia">Latvia</option>
                        <option value="Lebanon">Lebanon</option>
                        <option value="Lesotho">Lesotho</option>
                        <option value="Liberia">Liberia</option>
                        <option value="Libya">Libya</option>
                        <option value="Liechtenstein">Liechtenstein</option>
                        <option value="Lithuania">Lithuania</option>
                        <option value="Luxembourg">Luxembourg</option>
                        <option value="Macao">Macao</option>
                        <option value="Macedonia, The Former Yugoslav Republic of">Macedonia, The Former Yugoslav Republic of</option>
                        <option value="Madagascar">Madagascar</option>
                        <option value="Malawi">Malawi</option>
                        <option value="Malaysia">Malaysia</option>
                        <option value="Martinique">Martinique</option>
                        <option value="Mauritania">Mauritania</option>
                        <option value="Mauritius">Mauritius</option>
                        <option value="Mayotte">Mayotte</option>
                        <option value="Mexico">Mexico</option>
                        <option value="Micronesia, Federated States of">Micronesia, Federated States of</option>
                        <option value="Moldova, Republic of">Moldova, Republic of</option>
                        <option value="Nauru">Nauru</option>
                        <option value="Nepal">Nepal</option>
                        <option value="Netherlands">Netherlands</option>
                        <option value="New Caledonia">New Caledonia</option>
                        <option value="New Zealand">New Zealand</option>
                        <option value="Nicaragua">Nicaragua</option>
                        <option value="Niger">Niger</option>
                        <option value="Nigeria">Nigeria</option>
                        <option value="Niue">Niue</option>
                        <option value="Norfolk Island">Norfolk Island</option>
                        <option value="Northern Mariana Islands">Northern Mariana Islands</option>
                        <option value="Norway">Norway</option>
                        <option value="Oman">Oman</option>
                        <option value="Pakistan">Pakistan</option>
                        <option value="Palau">Palau</option>
                        <option value="Palestinian Territory, Occupied">Palestinian Territory, Occupied</option>
                        <option value="Panama">Panama</option>
                        <option value="Papua New Guinea">Papua New Guinea</option>
                        <option value="Paraguay">Paraguay</option>
                        <option value="Peru">Peru</option>
                        <option value="Philippines">Philippines</option>
                        <option value="Rwanda">Rwanda</option>
                        <option value="Saint Barthelemy">Saint Barthelemy</option>
                        <option value="Saint Helena, Ascension and Tristan da Cunha">Saint Helena, Ascension and Tristan da Cunha</option>
                        <option value="Saint Kitts and Nevis">Saint Kitts and Nevis</option>
                        <option value="Saint Lucia">Saint Lucia</option>
                        <option value="Saint Martin (French part)">Saint Martin (French part)</option>
                        <option value="Saint Pierre and Miquelon">Saint Pierre and Miquelon</option>
                        <option value="Saint Vincent and The Grenadines">Saint Vincent and The Grenadines</option>
                        <option value="Samoa">Samoa</option>
                        <option value="San Marino">San Marino</option>
                        <option value="Sao Tome and Principe">Sao Tome and Principe</option>
                        <option value="Saudi Arabia">Saudi Arabia</option>
                        <option value="Senegal">Senegal</option>
                        <option value="Serbia">Serbia</option>
                        <option value="Seychelles">Seychelles</option>
                        <option value="Sierra Leone">Sierra Leone</option>
                        <option value="Singapore">Singapore</option>
                        <option value="Sint Maarten (Dutch part)">Sint Maarten (Dutch part)</option>
                        <option value="Slovakia">Slovakia</option>
                        <option value="Slovenia">Slovenia</option>
                        <option value="Solomon Islands">Solomon Islands</option>
                        <option value="Somalia">Somalia</option>
                        <option value="South Africa">South Africa</option>
                        <option value="South Georgia and The South Sandwich Islands">South Georgia and The South Sandwich Islands</option>
                        <option value="South Sudan">South Sudan</option>
                        <option value="Spain">Spain</option>
                        <option value="Sri Lanka">Sri Lanka</option>
                        <option value="Sudan">Sudan</option>
                        <option value="Suriname">Suriname</option>
                        <option value="Svalbard and Jan Mayen">Svalbard and Jan Mayen</option>
                        <option value="Swaziland">Swaziland</option>
                        <option value="Sweden">Sweden</option>
                        <option value="Switzerland">Switzerland</option>
                        <option value="Syrian Arab Republic">Syrian Arab Republic</option>
                        <option value="Taiwan, Province of China">Taiwan, Province of China</option>
                        <option value="Tajikistan">Tajikistan</option>
                        <option value="Tanzania, United Republic of">Tanzania, United Republic of</option>
                        <option value="Thailand">Thailand</option>
                        <option value="Timor-leste">Timor-leste</option>
                        <option value="Togo">Togo</option>
                        <option value="Tokelau">Tokelau</option>
                        <option value="Tonga">Tonga</option>
                        <option value="Trinidad and Tobago">Trinidad and Tobago</option>
                        <option value="Tunisia">Tunisia</option>
                        <option value="Turkey">Turkey</option>
                        <option value="Turkmenistan">Turkmenistan</option>
                        <option value="Turks and Caicos Islands">Turks and Caicos Islands</option>
                        <option value="Tuvalu">Tuvalu</option>
                        <option value="Uganda">Uganda</option>
                        <option value="Ukraine">Ukraine</option>
                        <option value="United Arab Emirates">United Arab Emirates</option>
                        <option value="United Kingdom">United Kingdom</option>
                        <option value="United States">United States</option>
                        <option value="United States Minor Outlying Islands">United States Minor Outlying Islands</option>
                        <option value="Uruguay">Uruguay</option>
                        <option value="Uzbekistan">Uzbekistan</option>
                        <option value="Vanuatu">Vanuatu</option>
                        <option value="Venezuela, Bolivarian Republic of">Venezuela, Bolivarian Republic of</option>
                        <option value="Viet Nam">Viet Nam</option>
                        <option value="Virgin Islands, British">Virgin Islands, British</option>
                        <option value="Virgin Islands, U.S.">Virgin Islands, U.S.</option>
                        <option value="Wallis and Futuna">Wallis and Futuna</option>
                        <option value="Western Sahara">Western Sahara</option>
                        <option value="Yemen">Yemen</option>
                        <option value="Zambia">Zambia</option>
                        <option value="Zimbabwe">Zimbabwe</option>
                    </select>

这就是需要看的方式：https://harvesthq.github.io/chosen/
这是我所有css文件包含时的外观：

当我点击时：
这就是当我不包括chosen.css时的外观：

有人知道问题出在哪里吗？ 谢谢！