根据对话内容从方框内所给的选项中选出最佳答案，使对话完整，符合逻辑，句义通顺。注意：有多余选项。
A: You must be really excited about leaving for America tomorrow, Li Ping!
B: Yeah. {#blank#}1{#/blank#}
A: Nervous about what?
B: I don't know many of the customs and manners in the USA. {#blank#}2{#/blank#}
A: Sure.
B: {#blank#}3{#/blank#}
A: Well, it' s important to be on time when you're invited for dinner. {#blank#}4{#/blank#} Americans expect their guests to be on time.
B: Then how long may I stay there?
A: {#blank#}5{#/blank#} Or you seem to have come only for the meal. When your friends seem to be getting tired and running out of things, it's time to leave. The next day, call or write a thank-you note to say how much you enjoyed the evening.

A: Hi, Jason. Would you like to come over to my home this weekend?

B: {#blank#}1{#/blank#}What are we going to do together?

A: We're going to play chess on Saturday morning and I am going to cook noodles for you.

B: Are you joking?{#blank#}2{#/blank#}

A: Of course I can. I've learned cooking on TV.

B: {#blank#}3{#/blank#}

A: For two days. My parents have been away on business so I cook by myself.

B: When will they come back?

A:{#blank#}4{#/blank#} During these days, I have to do a lot of things alone.

B: I'm sure you will have a special experience.

A: Yes. {#blank#}5{#/blank#}I like trying new things.

B: You bet! See you then.

A: See you.

—________.

—       .We are facing a lot of environmental problems.