3．What can we infer from the underlined sentence in Para.4?

　　A．The author had a desire to communicate with the seniors.

　　B．The author wanted to do a chemical experiment with gas.

　　C．The author imagined himself to be part of isolated gas.

　　D．The author would like to be an oxygen molecule.

　　A　[推理判断题。作者起初并不愿意和老人们交流，而在与Colonel Hemsworth交谈后作者对老人的态度发生了变化，开始想和老人们交流互动，乐于倾听他们的智慧和经历。从画线句子可知，作者想融入其中，而不是被隔离，由此可推知，作者开始渴望和老人们交流。故选A。]

　　4．What does the sixth paragraph mainly tell us?

　　A．Other people's attitude towards volunteering.

　　B．The importance of communicating with others.

　　C．The important meaning of humans adapting to changes.

　　D．The lessons the author has learned from volunteering.

　　D　[段落大意题。通读第六段可知，本段主要讲述的是作者从做志愿工作中所获得的经验。故选D。]

　　B

　　The meaning of the word "volunteer" may be a little different in different countries, but it usually means "one who offers his or her services"．There are many different ways in which people can volunteer, such as taking care of sick people, working in homes for homeless children, and picking up garbage from beaches and parks. Volunteers may work within their own countries or in other countries. They are often people with a strong wish to help those who are less fortunate than themselves. Volunteers don't expect any kind of pay.

At the root of volunteering is the idea that one person may have the ability to offer services that can help other people. Tracy, a good friend of mine, however, recently came back from India with a new idea of what being a volunteer means. She worked for two and a half weeks in one of Mother Teresa's homes in Calcutta. The following is her story.