Complete the sentences with can or could (some sentences are in negative or interrogative).

5.a She ______________ take the stress of the exams. She now has to retake them.
5.b)
______________ I stay at my friend's house tonight?
5.c)
My friends ______________ talk for hours about the most different topics.
5.d)
______________ you help me move this TV, please? I'm going to give it to my cousin.