用所给动词的适当形式填空   

l. If I had a lot of money,I       (help) the poor  people.   

2. He isn't at home now. If he       (be) at home,I would see him.    

3. What      you____(do) if you missed the bus?    

4. You would probably go if it      (not rain).   

5. He____(be)healthy now if you helped him.  

6. He asked me if I       (be) new here.    

7. If you____ (be)more friendly to people, you will have more friends.    

8. I don't know if it_____ (rain) tomorrow. If it         (rain),I won't go there.    

9. My teacher asked if Mary       (finish) her homework yet.    

10. What if everyone else____(buy) snacks?

X、Y元素均为主族元素，_aX^m+和_bY^n-的电子层结构相同，下列叙述中错误的是[ ]

A．Y的原子序数小于X的原子序数

B．Y元素的核电荷b数等于a-m-n

C．的离子半径小于的离子半径

D．若X元素位于n周期，则Y元素位于(n-1)周期