12.下列条件中,不能判定四边形ABCD是平行四边形的是( )
| A. | ∠A=∠C,∠B=∠D | B. | AB∥CD,AB=CD | C. | AB∥CD,AD∥BC | D. | AB=CD,AD∥BC |
11.
如图,点O是平行四边形ABCD的对角线的交点,则图中全等三角形共有( )
| A. | 4对 | B. | 3对 | C. | 2对 | D. | 1对 |
10.已知函数y=$\frac{1}{x-3}$,自变量x的取值范围是( )
| A. | x≠3且x≠0 | B. | x>3 | C. | x<3 | D. | x≠3 |
8.下列各式计算正确的是( )
0 284696 284704 284710 284714 284720 284722 284726 284732 284734 284740 284746 284750 284752 284756 284762 284764 284770 284774 284776 284780 284782 284786 284788 284790 284791 284792 284794 284795 284796 284798 284800 284804 284806 284810 284812 284816 284822 284824 284830 284834 284836 284840 284846 284852 284854 284860 284864 284866 284872 284876 284882 284890 366461
| A. | 2$\sqrt{3}$×3$\sqrt{3}$=6$\sqrt{3}$ | B. | $\sqrt{28}$$÷\sqrt{7}$=2 | C. | $\sqrt{3}$+$\sqrt{7}$=$\sqrt{10}$ | D. | 5$\sqrt{3}$-3$\sqrt{3}$=2 |