The number of the students in our grade _____about nine hundred, _____of them are girls. A. are, two-fifths B. is, two- fifth C. is, two fifths.
---I want to buy the book Harry Potter. Do you know its _______? --- Not very well. Maybe fifty yuan.
---Would you mind moving the desk? --- _________. I will do it right away.
--- I hear a very big earthquake happened in Japan. Many people were injured or killed. ---___________________________.
---How long have you known the doctor ? ---_________he helped me three years ago.
---Never touch my computer while I’m away. --- Sorry, __________.