2．(2011山东高考)The two girls a re so alike that strang ers find ______ difficult to tell one from the other.
A．it B．them
C．her D．than
解析：考查代词的用法。句意：这两个女孩长得如此相似以至于陌生人很难把她们区分开来。在that引导的结果状语从句中， 谓语动词find的真正宾语是to tell one from the other，设空处需要形式宾语，而四个选项中只有it可以作形式宾语，所以选择A项。
答案：A
3．(2011天津高考)We feel ______ our duty to make our country a better place.
