英语语法选择题，求各位大神指点一下

英语语法选择题，求各位大神指点一下
l. It is necessary to put the medicine out of the kids' —— .
A. hold B. hand C. reach D. place
这个为啥选c不选b？
5. Many experiments have shown that moderate exercises contribute____ good health.
A. towards B. for C. with D. to
这个为啥选d不选c?
7. Her father's death _ her deeply.
A. affected B. effected C. offcnded D. infected
我选b，答案是a，请问两者有什么区别
8. "How do you _ the golbal warming?" the scientist asked the students.
A. count on B. account on C. count for D. account for
10. On second _, we decided not to sell our house.
A. plans B. thoughts C. ideas D. minds
11. Some plants are very sensitive _ the changes of the environment.
A.from B. against C. to D. with
12. I used to smoke__ but I gave it up a year ago.
A. seriously B. heavily C. badly D. severely
题目有点多，麻烦各位了，谢谢