IF引导的从句，求各位大神解答1、If you __(feel) lonely at any time, __(ring

IF引导的从句，求各位大神解答
1、If you __(feel) lonely at any time, __(ring) me up.
2、If he __(arrive) before I get back, __(give) him something to drink.
3、He promised me that if he __(get) into trouble he __(ask) for my working.
4、My boy never __(disturb) me if he __(notice) that I was woking.
答案1.feel ring; 2.arrives give; 3.got would ask; 4.disturbed noticed
IF引导的从句不是主句用将来时，从句用一般现在时么？为什么答案是上面几个？
看了半天是在实在是想不通为什么原因，求各位大神解答~~