eclipse 新建项目报错：The import android.support.v7.app cannot be resolved

在使用eclipse新建项目时报错：

Found 2 versions of android-support-v4.jar in the dependency list,
but not all the versions are identical (check is based on SHA-1 only at this time).
All versions of the libraries must be the same at this time.
Versions found are:
Path: F:\AndroidProjects_64\appcompat_v7\libs\android-support-v4.jar

Path: F:\AndroidProjects_64\AAA\libs\android-support-v4.jar

 Jar mismatch! Fix your dependencies

意思是v4包冲突 删除新建项目下的libs下面的v4包就ok了，搞不明白为什么新项目里引用了v7包了为什么还会有v4包