题干
Do you know _________ this time yesterday?
A：what she is cooking
B：what is she cooking
C：what she was cooking
D：what was she cooking
答案(点此获取答案解析）
C
。现将重物向下拉
，然后放手，则在刚释放的瞬间，重物加速度的大小是（
=
）
