题目

Why does Tom feel bad today?A.Because he's got a cough. B.Because he's got a fever. C.Because he's got a headache. 答案：【答案】C【解析】【原文】W: Morning, Tom. How are you feeling?M: Very bad, Mum. I’ve got a terrible headache. I’m afraid I can’t go to school today.如图所示，质量为m的物体静止于倾角为α的斜面体上，现对斜面体施加一水平向左的推力F，使物体随斜面体一起沿水平面向左匀速移动x，则在此匀速运动过程中斜面体对物体所做的功为 A．Fx　　　　　　　　　B．mgxcosαsinα C．mgxsinα             D．0