The road is covered with snow.I can’t understand they insist on going by motorbike.A. why

问题补充：

The road is covered with snow.I can’t understand they insist on going by motorbike.

A. why

B. whether

C. when

D. how

答案：

(答案→)A. why

B. whether

C. when

D. how

解析：考察宾语从句。句意：路上都覆盖着雪，我不能理解为什么他们坚持骑摩托车去那里。本句的考察主要集中在连接词的词义辨析上。BCD三项与句意不相符。上下文可知想知道具体什么原因。故A正确。