19世纪诞生的印象主义绘画,追求光色变化中表现对象的整体感。图9中,属于后期印象主义绘画代表作的有()
A.①②
B.①②③
C.①③
D.②③④
参考答案:C
_____ to ride a bike from your school to the park?[ ]
A. How long did you spend
B. How far did it take
C. How long did it take you
D. How far did you spend
质量为50kg 的何勇同学,在一次爬杆比赛中,用12s 爬到了5m 高的杆顶:
(1)何勇受到的重力是多少?
(2)何勇爬杆过程中做了多少功?功率多大?