—Smart phones are more and more popular now.—So they are. But they still ______ too much.
We don’t know _______ the meeting will be held soon.
--I’m worried about my English. -- ______ harder ________ you will catch up with your classmates.
I can’t go to the cinema with you because I _______ stay here until my mother comes back.
Let’s have_________ break; I want to make________ telephone call.
I don’t know how to begin a talk with Betty. She can sit all day long _______a word. A. by B. with C, in D. without