20.如图所示,图中共有( )个三角形.

| A. | 6 | B. | 8 | C. | 9 | D. | 12 |
16.走一段路,甲用2小时,乙用3小时,乙速度比甲慢( )
| A. | 50% | B. | 33.3% | C. | 16.7% |
15.把一个棱长总和是6分米的正方体铁块锻造成宽2厘米,高5厘米的长方体铁块,它的长是( )
| A. | 21.6厘米 | B. | 2.5厘米 | C. | 12.5厘米 |
13.下列各数按从大到小的顺序排列的是( )
0 158769 158777 158783 158787 158793 158795 158799 158805 158807 158813 158819 158823 158825 158829 158835 158837 158843 158847 158849 158853 158855 158859 158861 158863 158864 158865 158867 158868 158869 158871 158873 158877 158879 158883 158885 158889 158895 158897 158903 158907 158909 158913 158919 158925 158927 158933 158937 158939 158945 158949 158955 158963 199269
| A. | 40.2>40.2%>4.02% | B. | 40.2>40.2%>4.2 | ||
| C. | 40.2%>4.2>4.02% |