1. 从方框中选择适当的单词并用其适当形式填空。

probably, may, so, because, but

1. （1） I think Jack might be joking he smiled at us.
3. （2） Miss Yang isn't at the teachers' office. She be in our classroom.
5. （3） The twins said they would go to Australia for winter holiday.
7. （4） Jim got up very late this morning, he got to school on time.
9. （5） Mr. King lost his purse(钱包), he had no money to buy the ticket for the bus.