Chen: Thank you. But it’s your efforts that have made your stay so fruitful. Claudia: It’s really been an unforgettable experience. Let’s ( ).

But it's your efforts ....... that have made your stay so fruitful.

A、who
B、what
C、which
D、that

It’s your efforts that have made your stay so ________(富有成效的)

A、successful
B、fruitful
C、effective

A: Then let’s get your luggage and go to the hotel now. B: Oh, thank you.

Even if no RSVP has been requested, it’s ________ to thank your host for the invitation and let him know

A、

considerable   

thoughtless

thoughtful    

concerned