1. 招待客人随便吃时应该说：

A. Help yourself.
B. Thank you.

2. 表示感谢时说：

A. The same to you.
B. Thank you.

3. 晚上告别时应说：

A. Good evening.
B. Good night.

4. 给别人做示范时说：

A. Let me show you.
B. Let me try.

5. 当你想帮别人时应说：

A. Can I help you?
B. Can you help me?