on the exam 为什么不能用in the exam?

on the exam 为什么不能用in the exam? he spent a whole night () the desk for the math exam.A.on,B.at 为什么不能用on,只能用at! to my great joy ,i passed the exam and got an a in it.为什么只能用joy而不能用enjoyment There is a bird in the tree.为什么用In.能不能用on. 英语语法 in and onThe clound in the sky.为什么不能用on. on the exam和in the exam区别在哪?还有是cheat on the exam 还是in the exam? he failed in the exam,was expected为什么只能用AS 不用which Now that you failed the exam,you should get down to working hard now为什么不能用In that开头?As可以么? I passed the exam and I began to feel good about it中为什么不可以用in,with或on而用about呢?急呀, ---what made her sad?---___she failed in the exam A That 为什么是主语从句 为什么只能用 that you can't eat（）outside the dinner hall为什么什么都不填 难道at in on都不能用? i have been on the basketball team for a long time为什么介词不能用in join的延续性不就是be in He said he would never forget the day ___he spent with his girlfriend in the countryA.that　 B.when C.how 　D.where为什么不能用when.为什么这些句子都能用whenHe will never forget the day ___when__ he failed in the exam.I will never fo in exam 和in the exam区别 ___we will go camping tomorrow depends on the weather.为什么不能用if?只能用whether the pen that you want is on the desk 能不能用which 为什么为什么为什么 in the space station不能用in吗,必须用on? There is a bird in the tree.为什么是用in,不能用on,