（）是指承保被保险人依法对第三者应负的民事损害赔偿责任的保险。
A.人身保险
B.财产保险
C.信用保险
D.责任保险
参考答案：D
补全对话，每空一词。
A: Good morning.
B: Good morning. What are you 1 now？
A: I'm 2 .
B: Running？What's 3 with you bike？
A: It's 4 . Could you mend it？
B: Yes. I can. But now let's 5 games.
A: OK. What 6 the Frisbee (飞盘游戏)？
B: Good. Can you 7 it?
A: Yes, I can. Throw it 8 this.
B: No, you are 9 . Do it like this.
A: I know. It's very 10
1. ________ 2. ________ 3. ________ 4. ________ 5. ________
6. ________ 7. ________ 8. ________ 9. ________ 10. ________
如图所示，与水平面成θ角的皮带传送机，把质量为m的物体以速度v匀速向上传送，皮带作用于物体的摩擦力大小为______；支持力大小为______；这两个力的合力大小为______．
