问题补充:
The road is covered with snow. I can’t understand they want to go to school by motorbike.
A. why
B. when
C. since
D. that
答案:
(答案→)A. why
B. when
C. since
D. that
解析:考查宾语从句:A. why为什么B. when什么时候C. since自从D. that那么,根据句意:公路上都是雪,我不明白为什么他们想骑摩托车上学。选A。