4.已知999999×99999=99998900001,则9999990×999990=( )
| A. | 99998900001 | B. | 999989000010 | C. | 9999890000100 | D. | 99998900001000 |
3.已知等腰梯形的上底是10厘米,下底是25厘米,腰是15厘米,那么它的周长是( )厘米.
| A. | 65 | B. | 50 | C. | 70 | D. | 60 |
2.如图表示( )

| A. | 正方形个数最少 | |
| B. | 四边形包括梯形、平行四边形、长方形和正方形 | |
| C. | 梯形个数最少 | |
| D. | 平行四边形的个数比长方形和正方形个数多. |
1.与9999999相邻的数是( )
0 131756 131764 131770 131774 131780 131782 131786 131792 131794 131800 131806 131810 131812 131816 131822 131824 131830 131834 131836 131840 131842 131846 131848 131850 131851 131852 131854 131855 131856 131858 131860 131864 131866 131870 131872 131876 131882 131884 131890 131894 131896 131900 131906 131912 131914 131920 131924 131926 131932 131936 131942 131950 199269
| A. | 9999999和10000000 | B. | 9999998 和10000000 | ||
| C. | 9999999和88888888 | D. | 99999998和10000000 |