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