问题
选择题
---- I am not able to solve some practical problems using Newton’s First Law of Motion.
----That’s just _______ most of the students are puzzled easily.
A．what
B．why
C．how
D．where
答案
答案：D
where 引导的表语从句, where表示抽象的地点。句意：这正是大部分学生困惑之处。