A
The survival of about one fifth of the world's vertebrates—animals with a backbone，is considered threatened, according to new research published in the journal Science. That's a large fraction of Earth's animals, but this new study held some good news too. Conservation efforts by humans have slowed the loss of many species of amphibians(两栖动物), birds, and mammals. Losses in these groups would have been about 20 percent greater had it not been for recent actions of protection.
Among the animalconservation success stories is one about birds called Mauritius kestrels. In the 1970s, just four of these birds of prey were left in the world. Through a special breeding program, scientists were able to increase their number to about 1,000 and release them into the wild.
Humpback whales(座头鲸) have benefited greatly from recent conservation efforts as well. They were once on the International Union for Conservation of Nature's (IUCN)list of species threatened with extinction. But the species is now in less danger, thanks to laws that ban whale hunting. The IUCN even moved the humpback into “species of least concern.”
Over the past 100 years, the white rhino(犀牛) of South Africa has also made an amazing recovery because of habitat protection. The breed multiplied from just 50 animals to about 17,000. Their home has been turned into a protected area, safe from poachers and other threats.
Stuart Butchart, one of the authors of the new study in Science, is encouraged by the positive effects of conservation. But he says “Biodiversity (生物多样性)of species is in a desperate state. Its situation is getting worse. But our results show we can turn the situation around.”
New conservation policies hopefully are on the way. One hundred ninetythree countries recently met in Japan at the Convention on Biological Diversity to set concrete goals for preserving threatened wildlife and their habitats. Only 1 percent of oceans and 12 percent of land areas were protected under prior agreements. Two new goals set by the group are to designate(指定) 10 percent of the world's oceans and 17 percent of land environments as protected areas to help increase endangeredanimal populations.
21．What can we learn from the passage?
A．Though there was a special breeding program, the number of Mauritius
kestrels didn't increase.
B．Conservation efforts should not only be made by human beings.
C．Humpback whales are not on the International Union for Conservation of
Nature' s list now.
D．Because many groups are working to protect wildlife, natural habitats are in
good condition.
22．Which of the following is NOT mentioned in people' s conservation efforts?
A．Habitat protection.
B．Breeding programs.
C．Laws of banning whale hunting.
D．Creation of studying organizations.
23. The author uses some successful animalconservation examples to show
that________.
A．conservation works
B．man conquers nature
C．animals are more important
D．law is fair
CDA
