Why do researchers estimate elephant numbers in an area by counting dung piles ?

A．Because elephants are difficult to catch.

B．Because it is not possible to count elephants from a plane.

C．Because it is not possible to keep track of elephants.

D．Because elephants are shy animals.

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1 According to Plumptre, the region over which a dung-pile census is carried out should be

A．small enough.

B．well protected.

C．carefully monitored.

D．large enough

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2 The first word "He" in paragraph 6 refers to

A．Andrew Plumptre.

B．Katy Payne.

C．Anthony Chifu Nchanji.

D．the writer of the article.

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3 回答题
Sauna
Ceremonial (仪式性的) bathing has existed for thousands of years and has many forms, one of which is the sauna.The Finns have perfected the steam bath, or sauna, which may be taken, usually in an enclosed room, by pouring water over hot rocks or as a dry heat bath.    (46) Dry heat and steam baths had advocates in ancient Rome and pre-Columbian Americans used sweat lodges.
The earliest saunas were probably underground caves heated by a fire that naturally filled with smoke as chimney making was unknown at that time. A fire kept in a fire-pit would heat the rock walls of the cave. After reaching full heat, the smoke was let out of the cave and the stones would retain heat for several hours.   (47) Today most saunas use electric stoves, although gas and wood-burning stoves are available.
Saunas are relaxing and stress relieving.Those with muscle aches or arthritis (关节炎) may find that the heat relaxes muscles and relieves pain and inflammation (炎症). Asthma (气喘) patients find that the heat enlarges air passageways of the lung and facilitates breathing. Saunas do not cure the common cold but they may help to alleviate congestion (阻塞) arid speed recovery time.    (48)The sauna could be considered to follow the old saying “feed a cold, starve a fever”. The regular use of a sauna may decrease the likelihood of getting a cold in the first place.
Sauna is good for your skin as the blood flow to the skin increases and sweating occurs. Adults sweat about 2 lbs of water per hour on average in a sauna. A good sweat removes dirt and grime from pores and gives the skin a healthy glow. The loss in water weight is temporary as the body’s physiological mechanisms will quickly restore proper volumes.   (49) Heart rate may increase from 72 beats per minute on average to 100-150 beats per minute.
A normal heart can handle these stresses but those with heart trouble wishing to begin to use a sauna should seek a doctor’s advice. The elderly and those with diabetes should check with their doctor prior to beginning to take saunas.   (50) Indeed, everyone just starting out should take short sessions at first to become accustomed to this type of bath.

A．An extra large sauna and steam room can be used for players torelax in.

B．The cardio vascular system gets a work out as the heart must pumpharder and faster to move blood to the surface for heat exchange.

C．The Japanese, Greeks, Turks and Russians as well as NativeAmericans have forms of the sweat bath in their bathing rituals.

D．The body’s core temperature usually rises a 1-2 degrees while in the sauna,thus imitating a slight fever.

E．Pregnant women should not take saunas, particularly in the firstthree months.

F．A few people today say that the smoke sauna, “savusauna”, is the onlytrue sauna experience and that all saunas should have at least a backgroundodor or smoke.

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