如图所示，手对桌子作用一个力F₁，桌子也对手作用一个力F₂，则下列说法正确的是（   ）

补全对话(有两项多余)。

Lily: Hello, Tony. ____

Tony: Fine, thank you. And you?

Lily: Not bad. Mary and I planned to see the movie KongYiji tonight.

Tony: KongYiji? I have heard of it. ____

Lily: Lu Xun. Do you know him?

Tony: ____ Can you tell me something about him?

Lily: Sure! Lu Xun is one of the most famous writers in modern China. He is famous for novels, such as TheTrueStoryofAhQ.

Tony: Oh, I see. Can I go to see the movie with you?

Lily: Of course. 

Tony: ____

Lily: At 7: 30. 

Tony: ____

Lily: At 7: 20 at the cinema gate.

Tony: OK. See you then.

A. Who is it written by?

B. Who's your favourite writer?

C. No, I don't.

D. How are you these days?

E. When and where shall we meet?

F. How long will the movie be on?

G. When will the movie start?

已知两个共点力F₁和F₂不共线，若F₁的大小和方向保持不变，F₂的方向也保持不变，仅增大F₂的大小．在F₂逐渐增大的过程中，关于合力F的大小，下列说法正确的是（　　）

“低头族”长时间低头看手机，会引起颈部肌肉损伤．当头颅为竖直状态时，颈部肌肉的拉力为零，当头颅低下时，颈部肌肉会产生一定的拉力．为了研究颈部肌肉的拉力与低头角度大小的关系，我们可以建立一个头颅模型来模拟实验，如图甲所示．把人的颈椎简化成一个支点O，用1kg的头颅模型在重力作用下绕着这个支点O转动，A点为头颅模型的重心，B点为肌肉拉力作用点．将细线的一端固定在B点，用弹簧测力计拉着细线模拟测量肌肉的拉力，头颅模型在转动过程中，细线拉力的方向始终垂直于OB，如图乙所示．让头颅模型从竖直状态开始转动，通过实验记录出低头角度θ及细线拉力F的数据．如表：

低头角度θ/°	0	15	30	45	60
细线拉力F/N	0	7.3	14.0	20.2	25.0

车轮要做成圆形，实际上就是根据圆的特征（　　）