The worker has lived here fortwenty years______ A,since twenty years ago B,since he came here

问题描述:

The worker has lived here fortwenty years______ A,since twenty years ago B,since he came here
C,twenty years ago D.twenty years before

选B.从他来这里时起,他已经在这里住了20年了.
如果填A的话就变成了:从20年前起,他已经在这里住了20年了.