()1. The population of China is than that of Japan.

A.larger
B.bigger
C.more
D.fewer

A

英语中修饰population（人口）表示数量的大小，习惯用形容词large/small，不能用big、more、fewer；句中出现than，需使用形容词比较级，结合常识中国人口比日本多，因此用large的比较级larger。

()2. — has he been in this school?
—Since 2021.

A.How long
B.How often
C.How soon
D.How many

A

辨析四个疑问词组的用法：1. How long用于对时长提问，答语常为since/for引导的表时间段的内容；2. How often用于提问动作发生的频率；3. How soon用于提问“多久之后”，答语常为"in+一段时间"；4. How many用于提问可数名词的数量。本题答语为Since 2021，是表时长的内容，符合How long的使用场景。

()3. Not only my parents but also my sister to America last year.

A.have been
B.has been
C.have gone
D.has gone

B

1. 由not only...but also...连接并列主语时，谓语动词遵循就近原则，要和邻近的主语my sister（第三人称单数）保持一致，助动词需用has，排除A、C选项。
2. 辨析have been to和have gone to：have been to表示“曾经去过某地，现在已经返回原地”，have gone to表示“去了某地，目前还未返回”，结合语境此处描述过往的出行经历，用has been to符合逻辑，因此选B。

()4. He in this factory for 8 years.

A.has worked
B.works
C.working
D.worked

A

句中"for 8 years"是现在完成时的标志，表示动作从过去持续至今，现在完成时结构为have/has+动词过去分词，主语He是第三人称单数，助动词用has，work的过去分词为worked，对应选项A。

()5. We keep in touch WeChat.

A.by
B.in
C.om
D.with

A

本题考查介词词义辨析，by意为“通过，借助”，可用来引出做某事的方式/手段，此处表示借助微信保持联系，符合句意；in、on、with均不符合此处语境。

五、阅读理解。
The world's population is growing very fast. More than 250 babies are born every minute, and about 8 billion people live on the earth now. India has the largest population in the world, with about 1.43 billion people, and China has the second largest population.
The large population has caused many serious problems. It is difficult for us to provide enough food, water and energy for everybody. Traffic jams are very common in big cities, and pollution is becoming worse and worse. However, in developing countries, the population is growing much faster than in developed countries. Many people there still live a hard life. They do not have clean water or enough medicine, and some children cannot go to school.
With the rapid development of China, great changes have taken place in our country. Our living conditions have improved a lot. We have built more roads,
hospitals and schools. The government is trying its best to solve these population problems. We are also trying to protect the environment and make our country cleaner and more beautiful.
As middle school students, we should know the importance of controlling population and protecting our earth. We must study hard and try our best to make our world a better place for everyone.
根据短文内容，选择正确答案。
()1. How many people are there in the world now?
A. About 7 billion. B. About 8 billion.
C. About 9 billion. D. About 10 billion.
()2. Which country has the largest population?
A. India. B. China. C. The USA. D. Japan.
()3. What problems are caused by large population?
A. Not enough food and water. B. Heavy traffic and pollution.
C. Shortage of energy. D. All of the above.
()4. The population grows faster in countries.
A. developed B. developing C. western D. rich
()5. What are we doing to solve these problems?
A. Building more roads and hospitals. B. Protecting the environment.
C. Controlling population growth. D. All of the above.

1.B 2.A 3.D 4.B 5.D

1. 细节理解题，根据原文第一段“and about 8 billion people live on the earth now”，可知当前世界人口约为80亿，对应选项B。
2. 细节理解题，根据原文第一段“India has the largest population in the world, with about 1.43 billion people”，可知印度是世界人口第一大国，对应选项A。
3. 细节理解题，原文第二段提到人口过多带来的问题包括：难以给所有人提供充足的食物、水和能源，大城市交通拥堵普遍，污染越来越严重，A、B、C三项描述的问题全部存在，对应选项D。
4. 细节理解题，根据原文第二段“However, in developing countries, the population is growing much faster than in developed countries”，可知发展中国家的人口增长比发达国家快得多，对应选项B。
5. 细节理解题，原文第三段提到我们修建了更多道路、医院和学校，同时努力保护环境；第四段提到我们要了解控制人口的重要性，A、B、C三项描述的举措都属于我们为解决问题所做的行动，对应选项D。