15.在同一时刻,身高1.6m的小强的影长是1.2m,旗杆的影长是15m,则旗杆高为( )
| A. | 16m | B. | 18m | C. | 20m | D. | 22m |
14.在Rt△ABC中,∠C=90°,∠A、∠B、∠C的对边分别是a、b、c,则下列关系中错误的是( )
| A. | a=btanB | B. | a=ccosB | C. | b=csinB | D. | a=btanA |
8.某市自来水公司按如下标准收取水费:若每户每月用水不超过5m3,则每立方米收费1.5元;若每户每月用水超过5m3,则超过部分每立方米收费2元,小颖家某月的水费不少于15元,那么她家这个月的用水量(吨数为整数)至少是( )
0 309796 309804 309810 309814 309820 309822 309826 309832 309834 309840 309846 309850 309852 309856 309862 309864 309870 309874 309876 309880 309882 309886 309888 309890 309891 309892 309894 309895 309896 309898 309900 309904 309906 309910 309912 309916 309922 309924 309930 309934 309936 309940 309946 309952 309954 309960 309964 309966 309972 309976 309982 309990 366461
| A. | 10m3 | B. | 9m3 | C. | 8m3 | D. | 6m3 |