Question

几道高一英语改错题1>Miss Huang said our country has been using PSAs t

Answer 1

1 has - had 这里主句是过去时,所以从句 应该是过去完成进行时

2 falling - to fall warn sb to do sth 警告某人做某事

否定形式就是warn sb not to do sth

3 改为 how was sister now 这里从句是一般疑问句

4 on - for leave for 固定搭配,离开去某地 这里指为了生意表目的应该用

for,would 后面跟的是动词的原形,其他没错的,