题目内容：

if引导的条件状语从句不是主将从现?
下面句子是if 引导的条件状语从句,句子内容很长可以不用看,我想问的是,if 引导的条件状语从句,主句应该用将来时,从句用一般现在时（主将从现）,但是这里的主句和从句为什么都是各种各样的时态?if引导的条件状语从句时态到底应该遵循什么规律?
1.If it is not a question of resting the body,then perhaps it is the brain that needs resting（如果睡眠的功能不是在于使身体得到休息,那么也许是让大脑得以休息）【主句一般现在,从句一般现在】
2.If one group of people were disturbed from their eye-movement sleep for several nights on end,and another group were disturbed for an equal period of time but when they were no exhibiting eye-movements,（从句）
the first group began to show some personality disorders while the others seemed more or less unaffected.（主句）【主句从句都是过去时】
3.You may pick them up in utter exhaustion,if wind over the sea has driven them to a long journey【从句完成时】（如果海风驱使他们飞行很长距离,你可捡到一些因精疲力尽而掉下来的鹧鸪）
4.If one is obsessed with the success he has acheived,he would lose the chance to purse new sucess.【主句过去将来时,从句一般现在时】