题目

一个篮球运动员投篮一次得3分的概率为，得2分的概率为，不得分的概率为，，已知他投篮一次得分的期望是2，则的最小值为（   ） A．           B．            C．            D． 答案：DRewrite the sentences as required.1.You can hardly believe it. (改为反意疑问句)2.You mother is not so pushy as mine. (保持句意基本不变)3.Trees cool the air and trees clean the air, too. (保持句意基本不变)4.These people hardly care about the pollution in the city. (保持句意基本不变)5.Some kinds of fish release some black liquid to protect themselves from being killed. （保持句意基本不变）6.Both of them enjoy breathing the fresh air. (改为否定句)7.We should plant more trees to help protect our environment. (对划线部分提问)8.Without trees, the earth would get so hot that people couldn’t live on it. (保持原句意思)9.Building sandcastles at the beach is great fun! （改为感叹句）10.Have you got ready for the final exam? Our class teacher asked the students.（合并为一句）