C
The Tasmanian devil is a rare marsupial(有袋动物)that lives only on the Australian island state of Tasmania. The doglike animal is rapidly disappearing. The Tasmanian state government estimates that the number of devils has dropped from around 150,000 in the mid-1990s to between 20,000 and 50,000 at the end of 2007.
The devil was declared an endangered species last week. It is being wiped out by a rare cancer called devil facial tumor(肿瘤)disease(DFTD). It spreads like a cold or flu from animal to animal. The disease is passed when one devil bites another. When the marsupial is infected with DFTD, large tumors develop around its mouth and neck. These growths make it impossible for the devil to eat. Many finally die from starvation within six months of being infected. As the name implies, the disease occurs only in Tasmanian devils and cannot be passed to humans.
You’ve got to remember that devils are scavengers(清扫工). They search through garbage for food. Throughout Tasmania people maintain outdoor dumps. If somebody threw out a carcass(兽类尸体), then the devils might actually consume quite large quantities of it.
The disease has not yet appeared in the devil population that lives in the northwest region of Tasmania. Conservationists have captured some of the healthy devils and sent them to a new home on the mainland of Australia. They hope these DFTD-free marsupials can be used to start a captive-breeding population. Once there are more disease-free devils, they can then repopulate the areas of Tasmania where the species are being wiped out.
Tasmanian devils play an important role in keeping the state’s ecosystem in balance. They keep the population of other predators, such as foxes and wild cats, in check. Ray Nias, head of World Wildlife Federation—Australia’s conservation program, says all Tasmanian wildlife will suffer if the devil becomes extinct. “If the devils go and the foxes and cats increase, it would be all over for a good dozen or more species of mammals, many of which are unique to Tasmania.”
46. It can be inferred that the Tasmanian devil is __________.
A. a hard-working street-cleaner                        B. a grass-eating animal
C. a meat-eating marsupial                                D. A DFTD origin
47. What’s the reason for making the Tasmanian devil endangered?
A. A rare disease called DFTD occurs in Tasmanian devils.
B. Dogs like to attack Tasmanian devils.
C. Tasmanian people try to wipe out Tasmanian devils.
D. The region of Tasmania is becoming hard for Tasmanian devils to breed.
48. To which question does the last paragraph give the answer?
A. How should people protect the devils?
B. What do the Tasmanian people do with the devils?
C. What happens if the devils disappear?
D. Which animal is closely related to the devils?
49. What measures do Tasmanian people take to stop the devils from being wiped out?
A. Trapping disease-free devils in a new place to breed more young devils.
B. Searching the cause of the disease and finding an effective treatment.
C. Developing new chemicals for the infected animals.
D. Moving all the devils to a new home on the mainland of Australia.
50. What’s true about DFTD?
A. It’s a disease that can be spread to human beings.
B. It’s a cold that occurs only in Tasmanian devils.
C. It’s a flu that Tasmanian devils get from their companions.
D. It’s a cancer that can be passed from one Tasmanian devil to another.