In England, people often talk about the weather because they can experience four seasons in one day. In the morning the weather is warm just like in spring. An hour later black clouds come and then it rains hard. The weather gets a little cold. In the late afternoon the sky will be sunny, the sun will begin to shine, and it will be summer at this time of a day.

    In England, people can also have summer in winter, or have winter in summer. So in winter they can swim sometimes, and in summer sometimes they should take warm clothes.

    When you go to England, you will see that some English people usually take an umbrella (伞)or a raincoat with them in the sunny morning, but you should not laugh at them.

    If you don't take an umbrella or a raincoat, you will regret later in the day.

假如你是李明，学校领导和教师因为担心同学们浏览不健康的站，关闭了教室内电脑的络浏览功能，你们感到很难过。请你给校长写一封信，劝说校长同意开通教室内的络。信中要包括下表中的所有内容:

 
要求： 
1）表达清楚，语法正确，上下文连贯；
2）要点必须包括所有相关信息，并作适当发挥，但不得使用真实姓名和校名等；
3）词数：100词左右（信的开头和结尾已经给出，不记入总词数）；
4）建议措施不少于两点。
Dear Headmaster,
I'm writing to persuade you to let us surf the Internet in the classroom.                
   I do hope you can take my suggestion into consideration and let us get access to the Internet at school.                                                                         
     Looking forward to your reply.                                                 
Yours,
Li Ming

下列关于铜电极的叙述正确的是

 某烟气脱硫的工艺不仅能消除SO₂，还能将其转化为石膏（CaSO₄•2H₂O）等产品，实现“变废为宝”．主要物质转化关系如下：