I've got quite a few dictionaries. Among them, this English dictionary is ___________.
A:much useful
B:more useful
C:the most useful
D:a little useful
如图,放在粗糙水平桌面上的木块,受到F1=8N,F2=3N的水平推力 作用而处于静止状态。若撤去F1,则物体 ( )
如图所示是用传送带把货物从低处运到高处的情景.请结合图片回答下列问题: