Помогите пожалуйста!

Задание:Complete the sentences with must,cant or couldnt and use the correct form of the verb in brackets(Заполните предложения с обязательным условием, не можете или не можете использовать правильную форму глагола в скобках)

1)He revised well for the exam. He(Flunk) it.
2)His German is very good. He(grow up) in Germany.
3)You are not enrolling at university? Yo(be) serious!
4)Ann(be) hungry.She hasnt had anything sinse breakfast.
5)Is he going to study for a degree in Physics?He(be) mad;he has never been good at Physics.
6)He(play)football now;hes hurt his leg.
7)Shes late?but he(wait) for her still.
8) I(lose) my passport. Ive just seen it.
9)Susan knew everything.She(hear) our conversation.
10) I saw somebody through the window.They(be) out.

1. He couldn't flunk it2. He must be grown up 3. You must be serious4. Ann must be hungry5. He must be mad6. He can't play football7. but he must be waiting for her still8. I couldn't lose my passport9. She must heard our conversation10. They must be out