问题
选择题
It’s hot in the shopping mall, because the air-conditioning system ______.
A．broke up
B．broke down
C．broke in
D．broke out
答案
答案：B
题目分析:考查动词短语。A 驱散人群，学校放假；B 机器出故障，身体垮掉；C 破门而入；D 爆发。根据前后的因果关系判断，商场热是因为空调坏了，所以B选项正确。句意：因为空调系统出现故障，商场里很热。