【题目】Temperatures________ quite dramatically at night in mountains, so put on some warm clothes before going out.
A. are dropped B. drop
C. are being dropped D. have dropped
在线课程【答案】B
【解析】
试题分析：考查动词的时态和语态。句意：夜间山里的温度急剧下降，因此一定要穿上暖和的衣服再出去。该句描述一种经常发生的情况，故用一般现在时，故选B。