—Look at the sun! It's too hot today.
—Yes. Why not __________ your coat?
A:take off
B:take away
C:take out
D:take up
They were trying____ (cheat)the emperor.
在垂直于纸面的匀强磁场中,有一原来静止的原子核,该核衰变后,放出的带电粒子和反冲核的运动轨迹如图a、b所示,由图可知( )