----Has the teacher who was hurt in the earthquake been taken good care of?

----Ever since she was sent to the hospital, she has never been _______.

A．put out

B．left alone

C．looked after

D．fallen into

小明用如图甲、乙、丙的步骤探究摩擦力的大小与哪些因素有关．

（1）实验中，他应将弹簧测力计沿______方向拉动木块，使木块在水平面上做匀速______运动，并记下弹簧测力计的示数．

（2）比较步骤______与______可得：摩擦力的大小跟作用在物体表面上的压力有关，且压力越大，摩擦力越大．

比较步骤甲与丙可得：摩擦力的大小跟接触面的______有关，且接触面越______，摩擦力越大．