Playing computer games too much is bad _______ your eyes.
A：at
B：for
C：of
D：in
法兰克王国的建立者是（ ）
- Did you see _______ at the door? There is a boy waiting for you.
- No, I saw_______.
选择正确的选项补全对话。
A. welcome
B. water
C. Thank
D. like
E. Here
Tom: I'm thirsty. Can I have some ____?
Amy: Sure. ____ you are.
Tom: ____ you. I'd ____ an egg, please.
Amy: Here you are.
Tom: Thanks.
Amy: You are ____.
做匀加速运动的列车出站时，车头经过站台某点时速度是1 m/s，车尾经过该点时的速度是7 m/s，则这列列车的中点经过该点时的速度为 ( )
