3.如图几组图形中,( )的阴影部分占所在图形大小的50%.
A. | B. | C. | D. |
1.五年级男同学与女同学人数的比是5:4,男同学人数比女同学人数多( )
A. | $\frac{1}{5}$ | B. | $\frac{1}{4}$ | C. | $\frac{5}{9}$ | D. | $\frac{4}{9}$ |
20.校园里有8行柳树,每行a棵,杨树棵数比柳树多b棵.杨树有( )棵.
A. | 8b+a | B. | 8a+b | C. | 8b-a | D. | 8+a+b | ||||
E. | 8a-b |
19.下面的比中,( )可以和$\frac{1}{2}$:$\frac{1}{5}$组成比例.
0 157712 157720 157726 157730 157736 157738 157742 157748 157750 157756 157762 157766 157768 157772 157778 157780 157786 157790 157792 157796 157798 157802 157804 157806 157807 157808 157810 157811 157812 157814 157816 157820 157822 157826 157828 157832 157838 157840 157846 157850 157852 157856 157862 157868 157870 157876 157880 157882 157888 157892 157898 157906 199269
A. | 1:4 | B. | 2:5 | C. | $\frac{1}{10}$:$\frac{1}{4}$ | D. | 1:$\frac{2}{5}$ |