I can’t sleep the night before I take a big exam 改同意句 I can’t sleep the night before --a big-I can’t sleep the night before I take a big exam 改同意句 I can’t sleep the night before --a big exam

I can’t sleep the night before I take a big exam 改同意句 I can’t sleep the night before --a big-I can’t sleep the night before I take a big exam 改同意句 I can’t sleep the night before --a big exam
I can’t sleep the night before I take a big exam 改同意句 I can’t sleep the night before --a big-
I can’t sleep the night before I take a big exam 改同意句 I can’t sleep the night before --a big exam

I can’t sleep the night before I take a big exam 改同意句 I can’t sleep the night before --a big-I can’t sleep the night before I take a big exam 改同意句 I can’t sleep the night before --a big exam
改同意句吗?
I can’t sleep the night before taking/having a big exam.
before可做连词或介词,第一句中为连词,同意句中为介词.