Помогите, пожалуйста, правильно выбрать глагол.

2 (May/Might) I come in?

3 David (can/could) cook well when he wants to.

4 'Do you think it (can/might) rain?'

'Yes, possibly. We don't want to get wet so I think we (should/must) take our raincoats.'

5 Jenny tried to carry him but she {can't/couldn't).

6 We (can/might) visit my cousin in Australia next year but we don't know yet.