The World Needs Zoos
ZOOS play an important role in the world for conservation and education. They are particularly important for endangered species. Many animals are critically endangered and may go extinct in the wild, but in zoos, they are going strong. Many others are already extinct in the wild and only survive thanks to populations kept in captivity (圈养). Even those critical of zoos often recognize that it is better to have species preserved somewhere than lose them altogether.
Take the ring-tailed lemur (环尾狐猴) of Madagascar for example. This animal is almost ubiquitous in zoos as they breed well in captivity and the public are fond of them. However, despite their high numbers in collections around the world, they are the most threatened mammalian group on the planet. A recent survey suggests that up to 95 percent of the wild populations have been lost since 2000.
Such trends are not isolated. The giraffe is another very common species in zoos. Unlike the lemurs, giraffes are widespread in the countries across much of sub-Saharan Africa. Yet giraffe populations have gone down by a third in the last thirty years. While less dramatic than the drop in lemur numbers, this is obviously a major loss and again, whole populations (which some scientists think are of unique subspecies) are on the verge of extinction.
There will, I suspect, always be resistance to the argument for keeping animals in captivity and I will not defend the zoos that are bad and in desperate need of improvement or closure.
A.So we can see many endangered animals living in zoos. |
B.This is a trend that is only likely to continue. |
C.This means that the remaining individuals are at serious risk. |
D.In fact, species that are common can also come under serious threat before people realize it. |
E.But unfortunately that is not always the case. |
F.But if we wish to keep any real measure of biodiversity on the planet, we may have to lean on zoos far more than many realize. |

同类型试题

y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2


y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2

