综合实践活动是一门______。
A．独立的课程
B．自选课程
C．渗透的课程
D．地方课程
参考答案：C
If it had been fine yesterday, we could have watched that air show. But it _____ all day. [ ]
A. has rained
B. rains
C. rained
D. had rained
A．弹簧长度
B．弹簧材料
C．弹簧伸长量
D．拉力
