to, or, and, in

【1】The summer vacation is in July ________ August.

【2】I’ll sing ________ my mum on Mother’s Day.

【3】Tree Planting Day is ________ March.

【4】Mid-Autumn Day is in September ________ October.

【答案】

【1】and

【2】to

【3】in

【4】or

【解析】

略