（）与生态的改变和环境的污染密切相关。
A、雷雨
B、沙尘暴
C、冰雹
D、台风
参考答案：B
You can never imagine what great trouble I had ______ the poor boy who was seriously hurt. [ ]
A. help
B. to help
C. helping
D. helped
从事人体器官移植的义务人员允许（）
A.从事广告宣传
B.参与捐赠器官分配
C.参与抢救
D.参与死亡宣判
E.接受馈赠
