小明同学准备自制酸奶，他将新鲜牛奶加入适量蔗糖煮沸后装入消毒的大口玻璃瓶中，再将

为丙、丁、戊类厂房服务而单独设立的生活用房应按民用建筑确定，与所属厂房之间的防火间距不应小于()m。

A.6

B.7

C.8

D.10

书面表达。

     北京仁爱国际英语学校八年级学生魏环境向福州的网友李志愿发了一封电子邮件，询问了一些情况。请根据来信帮他回一封电子邮件。

     注意：1. 词数：60词左右；

                 2. 邮件的开头和结尾已替你写好，不计入总词数。

Receiver：Li Zhiyuan@163. com

Subject：How to protect the clean water?

Dear Li Zhiyuan, I feel very excited about my visit to Fuzhou and meeting you for the first time! But I’m still not sure about the following questions:1. Are there any rivers or lakes in your city? 2. Is the water dirty or clean? Why? 3. Did you do anything useful to protect the clean water? Please let me know. 

                                                                                                                                         Your friend，  

                                                                                                                                         Wei Huanjing  

Dear Wei Huanjing，

       I am very excited to receive your e-mail.  I am interested in your questions. _________________________________________________________________________________________________________________________________________________________________________________     

Looking forward to meeting you soon.

                                                                                                                                               Yours, 

                                                                                                                                             Li Zhiyuan

杜牧三十一岁时遇到了一名“老优伶美女”，旋即作了一首媲美《琵琶行》的诗作，诗文所寄之人是“花开堪折直须折，莫待无花空折枝”的作者，此“老优伶美女”是谁？

被困电梯怎么办？为什么不能强行扒门？

光伏发电系统中充放电控制器的主要功能包括（）。

A.高、低压断开和恢复

B.保护

C.欠电压告警和恢复

D.温度补偿