用所给词的适当形式填空。

1. This is our _____ (twelve) lesson, Tom, please listen carefully.

2. Does the key ring belong to ______ (I)?

3. I think we need about 15 ______ (loaf) of bread.

4. We look forward to ______ (win) the match.

5. Each of you ______ (have) a nice bike, right?

6. I ask my brother ______ (run) along the street.

7. — _____ Mary ______ (visit) her grandmother next Friday?

   — Yes, she is.

8. Take the second ______ (turn) on the right.

9. Look! The children are laughing _____ (happy).

10. The _____ (cook) in the kitchen are cooking nice food for people.

铰运算符的功能划分，运算符“+=”的类型是

A．算术运算符

B．关系运算符

C．逻辑运算符

D．赋值运算符