We have to__ourselves when we are away from home.

Those successful deaf dancers think that dancing is an activity ________ sight matters more than hearing.

Joe: Are you taking some gifts with you when you return to America?Dan: I’m planning to do so. Have you any suggestions?Joe: __________.

English is___ useful language because people in many countries are using it.

Loulan is believed __________ over by sandstorms gradually from AD