My keys are in my bag.             keys under that desk aren't mine.

---Are Mr. and Mrs. Wang living alone in the house? ---Yes, they have three sons, but ______ of them live in their own houses.

---Could you tell me __________ my English?---By listening and speaking more.

I found there was only one copy of “Bighead Son and Small-head Father” on the bookshelf, so I decided to buy _______ at once.

 —Do you know the girl?—Yes, ______ name is Linda.