A.will rain B. rains C. rained D. is rained

解析：答案B。真实条件句主句为将来时，从句用一般现在时。

3）_____ to do the work, I should do it some other day.

A. If were I B. I were C. Were I D. Was I

解析：答案C. 在虚拟条件状语中如果有were, should, had这三个词，通常将if省略，主语提前, 变成 were, should, had +主语的形式。但要注意，在虚拟条件状语从句中，省略连词的倒装形式的句首不能用动词的缩略形式。如我们可说 Were I not to do., 而不能说 Weren't I to do.

4). My suggestion is that she ________ more exercise, which will do a lot of

good to her.

A. takes B. must take C. take D. took 解析：错选A。本题要表达“我的建议是她（应该）多锻炼，这对她会有很大好处。”符合虚拟的条件，所以正确答案为C。空前面省略了should.