The TV is too loud. Could you please ________?
A:turn it on
B:turn it up
C:turn it down
D:turn down it
加速度的定义:____.
物理意义:____.
若函数f(x)=(a﹣1)x在(﹣∞,+∞)上单调递增,则实数a的取值范围是____.
80毫米和8分米一样长.____(判断对错)