The work of an elephant tamer also involves love and devotion. A good elephant tamer will spend hours a day singing love songs to a newly captured elephant. "Eventually they grow to love their tamers and never forget them. They are also more loyal than humans," she said, as she climbed up one of her elephants and sat on the giant, happy animal. An elephant princess indeed!

30. Before Parbati studied in a boarding school, ________.

A. she spent her time hunting with her father B. she learned how to sing love songs

C. she had already been called an elephant princess D. she was taught how to hunt tigers

31. Indian elephants are getting increasingly angry and they revenge because _____.

A. they are caught and sent for heavy work B. illegal hunters capture them and kill them

C. they are attacked and their land gets limited D. dogs often bark at them and chase them

32. The passage starts with an elephant story in order to explain that in India ______.

A. people easily fall victim to elephants' attacks B. the man-elephant relationship is getting worse

C. elephant tamers are in short supply D. dogs are as powerful as elephants

D

　　If doctors want to test you for something, they'll usually take a blood or urine sample(尿样). But wouldn't it be much more convenient if they just asked you to breathe through a special instrument?

　　In fact, your breath can say a lot about you. In traditional Chinese medicine, doctors draw a conclusion about the health state of a patient based on the smell of his or her breath; trained dogs and rats can identify the smells of the breaths of people suffering from certain cancers; traffic police also monitor drivers' alcohol consumption by testing their breaths.

　　Just like blood and urine, your breath contains lots of "metabolites" -the waste chemicals that the body produces, which vary from person to person. They are like personal health fingerprints, which is why scientists sometimes call them "breathprints", according to Science Daily.

　　Compared to blood or urine testing, breath testing takes only seconds instead of hours, and it requires neither a needle nor a container to hold the body fluids(液). This means the test can be taken frequently to better detect early signs of diseases and monitor the progress of a medical treatment.

　　On the other hand, as an identifier（鉴定物）, you might think that breaths are not as reliable as fingerprints since they might change based on what you eat. However, researchers in Zurich, Switzerland mapped 11 healthy volunteers' chemical patterns by having them breathe through a special instrument, and they found that each pattern was unique and the patterns didn't change much throughout the day, reported BBC.

　　"Our goal is to develop breath analysis to the point where it becomes competitive with the established analysis of blood and urine," said Malcolm Kohler, professor at the University Hospital Zurich.

33. According to the text we know that______.

A. breath varies from person to person based on food.