质量相等的铜和铝(铜的比热容小于铝) ,放出相等热量后相接触,热传递的方向是()
A:从铜传给铝
B:从铝传给铜
C:不发生热传递
D:不能确定
请在格子里涂黑,使得上图成为一个轴对称图形
如图所示,一小球m,用长L的悬线固定与一点O,在O点正下方 L2 处有一长钉.把悬线沿水平方向拉直后无初速度释放,当悬线碰到钉子瞬间( )
relaxing, on, hour, useful, an, and, finish, from, favorite, after
Dear Jack,
I am very busy____Friday. At 8:00 I have math. It is not fun. The teacher says it is____ but I think it is difficult.____ that, I have P.E. at 11:00. It is easy____fun. Lunch is____12:00 to 1:00. I have Chinese at 1:20. It is my____subject. My classes____at 2:00, but then I have____art lesson for two____. It is really____.
How about you?
Yours,
Lucy