题干
You __________ to leave until you __________ your work.
A：won’t be allowed; have finished
B：won’t allow; finish
C：won’t be allowed; will finish
D：won’t allow; will finish
答案(点此获取答案解析）
A
，电场方向水平向左，斜面高为H，则释放物块后，物块落地时的速度大小为
