Ответ:
1.I have a friend ___who___is very good at repairing cars.
2.A coffee-maker is a machine __which____makes coffee.
3.Why does he always wear clothes _which____are too big for him?
4.The man ___who____won the first prize last week will be very rich.
5.The books __which____are lying on the table are very interesting.
Объяснение:
Who используем, когда говорим про людей
Which используем, когда говорим про неодуш. предметы, явления и т.д.