1、The children were running on the playground as fast as they can.

改：can-could

解释：主句是过去进行时，从句也应该是过去时，保持一致。

2、Since her husband had died, so she had to support her family.

改：把so去掉。

解释：since表示原因，不需要so再来表示结果。两个词不能同时用在一个句子中。

3、He won't go out until his mother will come.

改：will come-comes

解释：主句是一般将来时，until引导的时间状语从句用现在时表示将来，改为第三人称单数。

4、He was very foolish that he didn't pass such an easy exam.

改：very-so

解释：so...that，如此……以至于。

5、Tom had gone out as soon as his mother got home.

改：had gone-gone

解释：主句用一般过去时。

6、It was three months since he came to our school.

改：was-is

解释：从过去到现在的一段时间，用现在时。

7、The platground of our school is larger than their school.

改：加上 that of (their school)。

解释：操场要和操场作比较，不是跟学校比。用that来指代。

8、The streets in Nanjing are wider than Shanghai.

改：those in (Shanghai)。

解释：街道要和街道比较。用those来指代复数的名词。

There are still many problems of environmental protection in recent years. One of the most serious problems is the serious pollution of air, water and soil. the polluted air does great harm to people’s health. The polluted water causes diseases and death. What is more, vegetation had been greatly reduced with the rapid growth of modern cities. To protect the environment, governments of many countries have done a lot. Legislative steps have been introduced to control air pollution, to protect the forest and sea resources and to stop any environmental pollution. Therefore, governments are playing the most important role in the environmental protection today. In my opinion, to protect environment, the government must take even more concrete measures. First, it should let people fully realize the importance of environmental protection through education. Second, much more efforts should be made to put the population planning policy into practice, because more people means more people means more pollution. Finally, those who destroy the environment intentionally should be severely punished. We should let them know that destroying environment means destroying mankind themselves.

目前环保还存在着许多问题。最严重的问题就是空气、水和土壤的严重污染。污染的空气对人类的健康十分有害。污染的水引起疼病，造成死亡。更有甚者，随着现代社会的迅速扩建，植被大大的减少。 为了保护环境，各国政府做了大量的工作。采用了立法措施控制大气污染，保护森林资源和海洋资源，制止任何环境污染。因此，在当今的环保中政府起着最重要的作用。 我的看法是，为了保护环境，政府应当采取更具体的措施。首先，应当通过教育的方法使人们充分謒到环境保护的重要性。第二，应更加努力把计划生育政策付诸实施，因为人口多就意味着污染严重。最后，要严惩那些故意破坏环境者。使他们破坏环境就是毁灭人类自己。

人教版英语教材是美式英语。

人教版英语教材一般是就教科书意义而言的，相对于其他出版社出版的教科书而言，指的是由人民教育出版社出版的教科书版本。而美式英语较英式英语来说更为口语化，读音开放，有特性。

过去的四百年间，美国、英联邦以及不列颠群岛使用的语言都在不断地发生变化，最终演变成了英式英语和美式英语。两种英语在音标、语法、词汇、拼写、标点、谚语、日期和数字的形式等等许多方面都有不同。

对于人教版的高中英语教材，单词拼写是按照英式英语标准来的，磁带录音用的却是美式英语。阅读材料里比较口语化的语言以美式英语居多。