2．After getting home from work, the author ________.

　　A．was very tired B．felt quite upset

　　C．was pretty lonely D．felt generally unwell

　　解析：选B　细节理解题。由第七段中的"fighting back tears"可知，作者回家后感到很不开心。

　　3．What did the author do after her first day of working with Rose?

　　A．She hurt Rose. B．She helped Rose.

　　C．She ignored Rose. D．She tolerated Rose.

　　解析：选D　细节理解题。由第七段中的"I decided to forgive her and try to get along with her."可知，与Rose 第一天合作后，作者开始包容Rose。

　　4．What can we infer from the text?

　　A．Never judge by appearances.

　　B．Friendship is love with understanding.

　　C．Misfortunes test the sincerity of friends.

　　D．Man has not a greater enemy than himself.

　　解析：选B　推理判断题。由最后两段尤其是文章末句"I've found that love is the best way to turn an enemy into a friend."可知，作者对Rose采取了包容的态度后两人关系变得和谐，作者逐渐理解了Rose，且两人最终成了朋友。据此可推断，友谊就是爱和理解。

　　B

　　Every time your fingers touch your cellphone, they leave behind trace amounts of chemicals. And each chemical offers clues to you and your activities. By analyzing them, scientists might be able to piece together a story about your recent life, a new study finds.

　　A molecule (分子) is a group of atoms. It represents the smallest amount of some chemical. Your skin is covered in molecules picked up by everything you've touched. With each new thing your skin contacts, you leave behind some small share of what it'd touched earlier.

　　Researchers at the University of California, San Diego (UCSD) recently analyzed such chemical leftovers on the phones of 39 volunteers. The study was led by biochemist Amina Bouslimani. To explore those residues (剩余物), the UCSD team wiped the surface of each volunteer's phone with a cotton swab (药签). The scientists also swabbed each person's right hand. Then the researchers compared the chemicals found on each cellphone.

The scientists discovered as many of the molecules as they could. They then compared these to a database of chemicals. Pieter Dorrestein, a UCSD pharmaceutical chemist, had helped set up that database a few years earlier, which contains various substances, including spices, caffeine and