RELATIVE CLAUSESComplete the sentences with who for people and that for

RELATIVE CLAUSES
Complete the sentences with who for people and that for things.
2. I can't find the key ________ opens this door.
3. It was a math ________ was difficult to win.
4. A waiter is someone ________ serves people in a restaurant.
5. There's a shop in our road _______ is open all time.
6. I met the girl _________ won the competition.
7. These are the letters _________ arrived this morning.
8. Which neighbour do you mean? The one _________ works in the bank?