My MP4 player isn't in my bag.Where___I have put it?

问题描述:

My MP4 player isn't in my bag.Where___I have put it?
A.can B.must C.should D.would 请顺便解释下原因

题意为:我的Mp4不在我包里.我把它放在哪里了呢?此处注意I have强调“已经”的义项.很关键.
首先排除B选项 must意为“应该,必须”,与I have矛盾;
看ACD三个选项,只有C选项should have done满足“应该已经把它放在哪里”之意.此处should表推测.