已知正实数m，若x¹⁰=a₀+a₁（m﹣x）+a₂（m﹣x）²+…+a₁₀（m﹣x）¹⁰，其中a₈=180，则m值为（　　）

①知之为知之，不知为不知，是知也。____

A．知道就是知道，不知道就是不知道，这就是明智的态度。

B．知道就是知道，不知道就是不知道，这就叫知道了。

②不耻下问____

A．不以向不如自己的人请教为羞耻。

B．不向不如自己的人请教为羞耻。

③默而识之____

A．默默地辨识它。

B．把学过的知识默默地记在心里。

④学而不厌____

⑤何有于我哉____

⑥逝者如斯夫____

A．逝去的人就像这流水一样啊！

B．逝去的（时光）就像这（河水）一样（一去不返）啊！

____ ____ your history teacher?

如图，在△ABC中，D、E分别是边AB、AC的中点，点F是BC延长线上一点，且CF=$\frac{1}{2}$BC，连结CD、EF．求证：CD=EF．

    My holiday is coming.Yesterday I asked my American friends about the best way to travel around the United States. They said it was best to travel by 1 and gave me the 2.

    To fly, of course, is the fastest way, but one can't see anything during a 3 except the blue sky and white clouds. So it is not very interesting for one who wants to see the 4.Besides, the plane ticket is very 5.

    To travel by train is 6, because passengers can walk and buy food and drinks on a train. They can also see cities and the country through the windows. But trains don't leave or 7 at a place every day, and don't go to many cities.

    To travel by bus is easy, cheap and convenient, though not so fast as travelling by plane or so 8 as by train. You can find buses almost in every city. That makes travel arrangement easy.

    I take their 9.Now I have decided to go on an interesting 10 by bus to the east coast.