完形填空。

    Hello, I am John. Look, this is a picture 1my room. I have a nice bed in the middle of my room. There is a big table 2 the closet and the bed. Many clothes are 3 the closet. A white air-conditioner is4 the wall beside the window. There is a computer on the table. I often write e-mails with it.

    Do you like my room? What's your room 5? Can you tell me, please?

已知⊙O半径为2,弦BC的长为$2\sqrt{3}$,点A为弦BC所对劣弧上任意一点. 则∠BAC的度数为____． 

文学艺术和体育运动的发展，让人们的生活变得更加健康、快乐、文明和幸福。

《新全球史》写道：“罗马人大约在公元前450年开始了成文法的传统，他们颁布《十二铜表法》作为共和国早期公民的基本法律。”从习惯法到成文法是法制的进步，它的颁布意味着（    ）