There ________ one basketball and two footballs on the floor. A. are B. is C. be
---How long have you known the doctor ? ---_________he helped me three years ago.
---Never touch my computer while I’m away. --- Sorry, __________.
---We had a football match with No. 15 Middle School yesterday. ---________. I missed it.
---How did the accident happen? ---You know, it ________difficult to see the road clearly because it_________.
---My house is very near a busy street. ---It ________ be very quiet.