设$P=\frac{1}{{\log }_{2}11}+\frac{1}{{\log }_{3}11}+\frac{1}{{\log }_{4}11}+\frac{1}{{\log }_{5}11}$则（   ）

如图所示，一质量为m的小球，用长为L的轻绳悬挂于O点，初始时刻小球静止于P点。第一次小球在水平拉力F作用下，从P点缓慢地移动到Q点，此时轻绳与竖直方向夹角为θ，张力大小为T₁；第二次在水平恒力F′作用下，从P点开始运动并恰好能到达Q点，至Q点时轻绳中的张力为大小T₂。关于这两个过程，下列说法中正确的是（     ）

A: Have you learned Topic 2, Unit4?  

B: No, not yet. We will begin to learn it next week.

A: But we've learned it. It's about some ____ like Edison, a great American inventor.

B: I have read about Edison in a book, so I know ____ about him.

A: Really?

B: Yes. He invented a lot of things. And they all have ____ the world.

A: I know he was born in 1847, and died in 1931.

B: So he has been ____ for more than eighty years.

A: Yes, but we can remember him every day.

B: Sorry, I don't understand ____ you mean.

A: Do you give your friend a call every day?

B: Yes. Oh, I see. Edison invented the telephone.

Going to the movies is good, ______ I really only like listening to music. 

看电影吃爆米花是一种纯正的美式习俗，但20世纪20年代美国五大影院在观影时是禁吃爆米花的，看电影吃爆米花真正流行于30年代，随后风靡全球。这种改变最能说明(   )