(1) Please be quiet. I ___ the speaker very well.
a.can't hear b.am not hearing c.couldn't hear
答案是a，
但是我有疑问，如果上列句子是出现在寓言、过去时态里，
难道不应该用c 吗?
(2) ___ help me carry this box?
a.Would you b.Do you c.Could you d.Let's
答案是a & c,
可加选b 吗?