央视“3.15”特别节目曝光，某品牌肉制品中含瘦肉精．某种瘦肉精的化学式C₁₂H₁₉Cl₃N₂O，下列有关说法正确的是（　　）

A．该瘦肉精是有机物

B．该瘦肉精分子中含有氮分子

C．该瘦肉精由碳、氢、氯、氧四种元素组成

D．瘦肉精由12个碳原子、19个氢原子、3个氯原子、2个氮原子、和1个氧原子构成

根据对话内容，在空白处填入适当的句子、短语或单词，使对话意思完整，通顺。

A: Hello, Jane. This is Maria speaking. Would you like to go hiking with us this Saturday?

B: 1.                                 . But I'm afraid I'll have to go to the library.

A: What about next Saturday?

B: 2.                                 . Let's go hiking then.

A: OK. I hope the weather will be fine then.

B: I am sure it will. 3.                                      .

A. Let's meet at half past seven.

B: Why not make it earlier, 4.                                       .

A: That sounds good. Where shall we meet?

B: 5.                                   .

A: Great! See you then!

B: See you!