if we haven't 和if we hadn't在用法上有什么不同?If we hadn't got everything ready by now,we should be having a terrible time tomorrow.句中的 hadn't换成haven't可以吗?

if we haven't run out of our braver if we haven't 和if we hadn't在用法上有什么不同?If we hadn't got everything ready by now,we should be having a terrible time tomorrow.句中的 hadn't换成haven't可以吗? haven’t we told you that you ___have 20 dollars if you fix our computer? We haven't decide ___ to go to Beijing(whether,if) We haven't known ____ there is life on Mars.A.that B.if C.what D.and we havent settled the problem 什么什么 it is necessary for him to study abroadA,if Bwhere Cwhether Dthat We haven`t decided if _____ .选词填空1.will take we a field trip 2.we take a field trip 3.we takes a field trip4.we`ll take a field trip if i didn't met you和if i haven't met you 的区别是? 英语翻译if we . If we belong together if only we belive If we exerxise every If We Ever damned if we do,damned if we don't怎么翻译啊? --How we need another motorcar!--If only we ____so much money on our vacation.A,won't have spentB,wouldn't have spentC,hadn't spentD,haven't spent 英语：同义句转换We haven't met for a long time___ ___ ___ ___since we met last time.If we beat them in the match,we will be the best.if we ___ ___ ___,we will be the___.You should return the book to the library on time.You should___the bo I still remember my first teacher( ）we haven't seen each other for a long time.A.if B.until C.though D.because what if our parents know we haven't finished the work? _____I have no idea you are right you are welcome that's right