—Look at the boy running on the ground. Is it David?—It be him. I saw him go to the teacher’s office just now.
---Who teaches______singing? ---Nobody, I learn it by_______.
There is____with my computer. Can you help me mend(修理) it?
---How was your vacation? ---_______. I liked it very much.
I have quite_____friends. I feel very happy.
---Where did Jenny go on vacation? ---She went______.