问题补充：
Don you know , my dear friend, it is you that she loves?
A. who
B. which
C. that
D. what
答案：
A. who
B. which
(答案→)C. that
D. what
解析：that引导的是一个宾语从句（用做动词know的宾语），它只是被句中的插入语my dear friend隔开罢了。其实此句也可说成：My dear friend, don you know that it is you that she loves?
