问题补充:
The math problem is so hard. I really don’t know.
A. how to do it
B. how to do
C. what to do it
D. where to do it
答案:
(答案→)A. how to do it
B. how to do
C. what to do it
D. where to do it
解析:how如何,怎样;what什么;where在哪儿。句意:这道数学题是这么难。我真的不知道如何解答。选项B缺少逻辑宾语,结合语境可知选A。