1：(When) you (are) free,(can) you (help) doing the housework?
2:Why (do) you wait (here) so long?--(Because) I (have to do)
还有一些有疑问的：
1：The old woman (lives) (all) (by herself).She is (alone).
2：The street (is) (very) (crowding) (during) New Year's Day.

以前这些题是找错误的词语， 一句只有一个，
有疑问的第一个我是把alone改成lonely，第2个是把crowding改成crowd，不知道对不对，
还有上面2个题拜托各位大哥大姐说答案的时候请把理由也说一下，。
谢谢。。

1：(When) you (are) free,(could) you (help) doing the housework? 这样改语气更加委婉.
2:Why (do) you wait (here) so long?--(Because) I (have to ) 省略do,保留情态动词.
还有一些有疑问的：
1：The old woman (lives) (all) (by herself).She is (lonely).
孤身一人住,会感到寂寞的.这就是两个词的区别
2：The street (is) (very) (crowded) (during) New Year's Day.
拥挤,用 crowded,这是过去分词作形容词



参考文献：calendula28