为什么我不能在Android Studio中添加支持库？

Question

buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:0.8.+'
    }
}

dependencies {
    compile 'com.android.support:appcompat-v7:19.0.+'
    compile 'com.android.support:support-v4:19.0.+'
    compile 'com.github.chrisbanes.actionbarpulltorefresh:library:+'
    compile 'com.actionbarsherlock:actionbarsherlock:4.4.0@aar'
    compile project(':library:SlidingMenu:library')
    compile project(':library:Android-ViewPagerIndicator:library')
    compile fileTree(dir: 'libs', include: ['*.jar'])
}

apply plugin: 'android'

android {
    compileSdkVersion 19
    buildToolsVersion "19.0.1"

    defaultConfig {
        minSdkVersion 8
        targetSdkVersion 19
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            runProguard false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'
        }
    }
}

事件日志

无法刷新Gradle项目“我的应用程序”无法在项目'：app'上找到参数[com.android.support:appcompat-v7:19.0.+]的方法compile（）。请从Android SDK Manager安装Android支持存储库。