表示事实,前后都用符合事实情况的时态。
If I get sick, I go to the doctor.
表示将来有可能,前现在时,后将来时
If I get sick, I will go to the doctor.
表示将来不太可能,前过去时,后 would + do
If I got sick, I would go to the doctor.
表示后悔过去的事,前过去完成时,后 would + have/has done
If I had been sick, I would have gone to the doctor.
这个题后面是would probably want,那就是第三种,would + do
所以前面就是过去时,were