15.
如图,在△ABC中,DE∥BC,AE:EC=2:3,DE=4,则BC的长为( )
| A. | 10 | B. | 8 | C. | 6 | D. | 5 |
12.下列四个不等式:①-$\frac{2}{3}$<-0.67;②-$\frac{1}{4}$>-0.24;③-$\frac{5}{6}$>-$\frac{4}{5}$;④-$\frac{3}{11}$<$-\frac{1}{4}$.其中正确的是( )
| A. | ②④ | B. | ①③ | C. | ②③ | D. | ④ |
7.不等式组$\left\{\begin{array}{l}{3-x>0}\\{\frac{x}{2}+1≥\frac{x}{3}}\end{array}\right.$的整数解的个数为( )
| A. | 6 | B. | 7 | C. | 8 | D. | 9 |
6.如图四个几何体,其中,它们各自的主视图与俯视图不相同的几何体的个数是( )

0 283051 283059 283065 283069 283075 283077 283081 283087 283089 283095 283101 283105 283107 283111 283117 283119 283125 283129 283131 283135 283137 283141 283143 283145 283146 283147 283149 283150 283151 283153 283155 283159 283161 283165 283167 283171 283177 283179 283185 283189 283191 283195 283201 283207 283209 283215 283219 283221 283227 283231 283237 283245 366461
| A. | 1 | B. | 2 | C. | 3 | D. | 4 |