问题
选择题
We _______ pay to get into the concert. It's free.
A．can't
B．mustn't
C．might not
D．don't have to
答案
答案：D
题目分析：句意：我们进入音乐会不必付钱。这是免费的。A. can't 不可能； B. mustn't 禁止； C. might not 可能不； D. don't have to不必。根据It's free.可知音乐会是免费的，因此不必付钱。故选D。