更多"The shrinking range poses （）to Afri"的相关试题:
[单项选择]Africa’s elephants are divided between the savannahs of eastern and southern Africa and the forests of central Africa. Some biologists reckon the forest ones-smaller, with shorter, straighter tusks-may even constitute a distinct species. But not for long, at the latest rate of poaching. The high price of ivory is increasing the incentive to kill elephants everywhere in Africa, and especially in places where there is virtually no law.
The latest reports suggest that the forest elephant population is collapsing on the back of rising Chinese demand for ivory. Some conservationists argue that a recent decision by the Convention on International Trade in Endangered Species (CITES) to auction 108 tonnes of stockpiled ivory from southern Africa may be prompting more poaching in central and eastern Africa, as criminals seek to mix illicit ivory in with the legitimate kind. But some economists maintain that the legitimate sale of ivory lowers prices, thus decreasing the incentive to poach
A. Biological evidences are insufficient to support this point of view.
B. The high price of ivory entices more killings of elephants.
C. Their number is too small to be of a species.
D. A serious disease broke out among the elephants and sharply decreased their number.
[填空题]Until about two million years ago, Africa’s vegetation had always been controlled by the interactions of climate; geology, soil, and groundwater conditions; and the activities of animals. The addition of humans to the latter group, however, has increasingly rendered unreal the concept of a fully developed "natural" vegetation—i.e., one approximating the ideal of a vegetational climax.
(16)
Early attempts at mapping and classifying Africa’s vegetation stressed this relationship. sometimes the names of plant zones were derived directly from climates. In this discussion the idea of zones is retained only in a broad descriptive sense.
(17)
In addition, over time more floral regions of varying shape and size have been recognized. Many schemes have arisen successively, all of which have had to take views on two important aspects, the general scale of treatment to be adopted, and the degree to which human modification is to be comprehended or
[填空题]
Until about two million years ago Africa’s vegetation had always been controlled by the interactions of climate; geology, soil, and groundwater conditions; and the activities of animals. The addition of humans to the latter group, however, has increasingly rendered unreal the concept of a fully developed "natural" vegetation-- i. e. , one approximating the ideal of a vegetational climax. (41) _____________________. Early attempts at mapping and classifying Africa’s vegetation stressed this relationship: sometimes the names of plant zones were derived directly from climates. In this discussion the idea of zones is retained only in a broad descriptive sense.
(42) _____________________. In addition, over time more floral regions of varying shape and size have been recognized. Many schemes have arisen successively, all of which have had to take views on two important aspects: the general scale of treatment to be adopted, and the degree to which human
