关于力和力偶对物体的作用效果,下列哪些说法是正确的()。
A.力只能使物体移动
B.力可以使物体移动和转动
C.力偶只能使物体移动
D.力偶只能使物体转动
参考答案:B, D
读图,正确的说法是( )
A.从甲处攀登山峰最远,最费力
B.从乙处攀登山峰较远,最省力
C.从丙处攀登山峰较远,最费力
D.从丁处攀登山峰最远,最省力
There are many disadvantages in grouping pupils just according to their intellectual ability. In fact, bright children are rarely_____by mixed ability teaching.
A.held out
B.held back
C.held up
D.held in