⑴We can't swim in the lake?____                                        A.

⑵There is a toilet here.____                                                B.

⑶We should keep quiet in the library.____                         C.

⑷We can't walk on the grass.____                                       D.  

⑸We can eat here.____                                                        E.

断开1mol H一H键、1mol N一H键、1mol N≡N 键分别需要吸收能量为436kJ、391kJ、946kJ，求：H₂与N₂反应生成0.5molNH₃填____ （“吸收”或“放出”）能量____ kJ．

  ①罗马法是近代很多西方国家法律的基础

  ②《权利法案》是世界上第一部资产阶级成文宪法

  ③1787年联邦宪法确立了君主立宪的政治体制

  ④《拿破仑法典》确立了资本主义社会的立法规范

请阅读Tony从美国发来的电子邮件，以李华的名义写一篇80词左右的回复。文中不得出现真实的人名、校名与地名。

Hey Li Hua

How are you? I've been busy since I came back from China. Guess what! I'm learning Chinese very hard, but I find it really difficult to learn Chinese well. Please tell me the best way you think.

One more thing, I hear you have Mid-Autumn Festival in China. What's the date of the festival? How do you celebrate?

Tony