We all helped him with his English so he didn't * with his study._英语解答

We all helped him with his English so he didn't * with his study.
*处应选哪个答案：
A:fall off B.fall down C.fall behind D.fall over

人气：279 ℃　时间：2019-11-11 23:24:44

解答

C.fall behind 落后落伍
fall off 从…摔下来 fall down 从高处摔下 fall over 摔倒 fall behind 落后 7