Ответ:

1 They must have got our  money.

2 She might will arrive this afternoon.

She could will arrive this afternoon.

3 They can't be brother and sister.

4 He might be Spanish or Italian.

He could be Spanish or Italian.

5 He can't be the new manager.

6 She must be in the office.

7 The bag might belongs to Helen.

The bag could belongs to Helen.

8 It must be his fault.

Объяснение: