用“平移 ”或“旋转”填空。
①时钟:____ ②木块的移动:____ ③开门:____
End of Term Report
Student's name
Zhang Xing
Subject
English
Teacher
Mr. Dickens
At the beginning of this term
He found that studying English was very ____
In writing
His ____is better.
In speaking
He can have English ____with his friends and with me.
He can answer my questions in English____.
Next term
If he ____like this, he will do much better.
一个英俊的少年骑着白马沿辽河东行,来到上游的木叶山,遇见一个乘青牛的美丽少女。两人互相爱慕,结为夫妻。传说他们就是我国北方古老的契丹族的祖先。公元10世纪初,统一了契丹各部的首领是( )
如图所示,是同一滑轮组的两种不同的绕法,用它们提起相同的重物,比较两种情况下所用的拉力F1、F2和机械效率η1、η2(不计绳重及摩擦),下列说法中正确的是 ( )