gradle sync问题（不确定依赖项中的编译

Question

我的build.gradle文件中存在问题，实际上让人感到困惑 编译＆＃39; com.android.support：appcompat-v7：27.1.1＆＃39;哪个版本我应该写它我的代码片段如下，任何帮助将不胜感激。

apply plugin: 'com.android.application'

android {
    compileSdkVersion 27
    buildToolsVersion "27.0.3"

    defaultConfig {
        applicationId "com.example.android.sunshine.app"
        minSdkVersion 15
        targetSdkVersion 27
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
    buildTypes.each {
        it.buildConfigField 'String', 'OPEN_WEATHER_MAP_API_KEY', "\"f4a03a30897d9df5d6afa15c7c624d6c\""
    }
}

dependencies {
    implementation 'com.android.support.constraint:constraint-layout:1.1.1'
    implementation 'com.android.support:design:27.1.1'
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.android.support:appcompat-v7:27.1.1'

}