已知a＞b＞0，椭圆C₁的方程为$\frac{x^2}{a^2}+\frac{y^2}{b^2}=1$，双曲线C₂的方程为$\frac{x^2}{a^2}-\frac{y^2}{b^2}=1$，C₁与C₂的离心率之积为$\frac{\sqrt{3}}{2}$，则C₂的渐近线方程为（　　）

有些幼儿常服钙片，仍因缺钙患佝偻病，原因可能是缺乏（　　）

①要自觉遵守中学生守则，遵守校纪校规②要自觉履行九年义务教育的义务③要培养高雅的情趣爱好，拒绝不良诱惑④不良习惯一旦形成，就无法改变

阅读下面对话，从方框中选择适当的句子补全对话。

A: Hello, Jane. The weekend is coming. ____

B: Yes, I'd love to. But where shall we go?

A: What about the Palace Museum? ____

B: That's really a wonderful place to visit. Then what can we do there?

A: ____

B: That sounds great. How can we go there?

A: The best way is to take the underground. ____

B: All right. ____

A: Shall we meet at my home at 8 a.m. tomorrow?

B: OK. See you tomorrow.

A: See you.