1.  Jack ________ (be) late this morning because he missed the early bus.
2. Mrs White is in the classroom now. She________ (talk) with some students.
3. ---Are there any apples in your shop, madam?  
    ---Sorry, we ________ ( not sell ) any fruit.
4. Now we are doing our best ________ (learn) English well.
5. I ________ (take) care of my lovely dog until the end, I think.
6. When I was doing my homework at home, I heard her________ (call) for help.
7. If it________ (snow) tomorrow, we'll watch TV at home instead of going diving.
8.The girl often ________ (swim) alone in the river when she was very young.
9. It's very important ________ (not give) your goldfish too much food.
10. They always have a great time ________ (chat) with each other.