1 . Charles enjoys ________ photos very much so he always goes out with his camera.

A．take

B．taking

C．to take

D．to taking

2 . What ____________ (颜色) is the pen?

3 . “x与y的差”用代数式可以表示为_______

4 . 你学校每学期都有郊游吗？
Do you have a school trip ________ ________?

5 . 碰到许久未见的同学，你可以这样说：
____________________________.

6 . I want to be a ________ (科学家) in the future.

7 . The human brain ________（weigh）about 1.4 kilograms, but it can hold much more information than most computers.

8 . John goes on a short j________ in the boat.

9 . The teacher always tells us the_________(important)of being an honest man．

10 . Liu Yang, an ________（优秀的） astronaut, is the first Chinese woman to go to outer space（太空）.