Question

【题目】____ is difficult to know how to ask for help politely.

A. This B. That C. It D. These

Answer 1

【答案】C

【解析】句意：懂得如何礼貌地请求帮助会很困难。A. This这个；B. That那个；C. It 它；D. These这些。句型“It’s+adj.+ to do sth.”意思是“做某事怎么样”，It为形式主语，不定式是真正的主语，故答案为C。