AS中加载gradle时出现Gradle sync failed: Could not find com.android.tools.build:gradle.的错误

1 Gradle sync failed: Could not find com.android.tools.build:gradle:3.5.0.  
2          Searched in the following locations:  
3          file:/F:/studio/studio2.0/gradle/m2repository/com/android/tools/build/gradle/2.8/gradle-2.8.pom  
4          file:/F:/studio/studio2.0/gradle/m2repository/com/android/tools/build/gradle/2.8/gradle-2.8.jar  
5          https://jcenter.bintray.com/com/android/tools/build/gradle/2.8/gradle-2.8.pom  
6          https://jcenter.bintray.com/com/android/tools/build/gradle/2.8/gradle-2.8.jar  
7          Required by:  
8          :TestApk:unspecified  
9          Consult IDE log for more details (Help | Show Log)

 1 buildscript {
 2     repositories {
 3         //添加
 4         google()
 5         jcenter()
 6     }
 7     dependencies {
 8         classpath ‘com.android.tools.build:gradle:3.1.1‘
 9 
10         // NOTE: Do not place your application dependencies here; they belong
11         // in the individual module build.gradle files
12     }
13 }
14 
15 allprojects {
16     repositories {
17 　　　　 //添加
18         google()
19         jcenter()
20     }
21 }
22 
23 task clean(type: Delete) {
24     delete rootProject.buildDir
25 }