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- 15. —Why didn't you come to the meeting?
- 2do you hear ming --- in the next room?1,sing 2,to sing 3,singing
- 3用小正方体拼一个立体图形,使得从左面看和从上面分别得到下面两个图形.
- 4We bought some computers last week,but ____（two；five） of them do not work well.
- 5澄清石灰水的化学式不是化学方程式
- 6A book holds a house of gold
- 7乘数有a位小数,被乘数有b位小数,那么它们的乘积不会超过a+b位小数,
- 8边长为10cm的正方形,重60牛,放在面积为0.6平方米的水平桌面上,则该物体对桌面的压强
- 9已知角AOB=90度,在角AOB的平分线OM上有一点C,将一个三角板的直角顶点与C重合.
- 10已知数列an中,a1=2,an+1=4an-3n+1,bn=an-n,求证数列bn为等比数列,求an前n项和