灭绝的

How many mass extinctions have there been, and what are the important ones?

曾有过多少次大灭绝？哪些是重要的？

Humans are causing extinctions now, because of pollution and other damage to the environment.

由于污染和其他对环境的破坏，人类在人为地制造物种灭绝。

Throughout the history of life extinctions have been occurring.

在生命的长河中，物种灭绝现象一直都在发生着。

"The major mass extinctions tend to be treated in isolation," Peters says.

&主要的生物大灭绝往往被隔离治疗，，&彼得斯说。

Perhaps, extinctions are caused by something outside, like comets and asteroids.

也许，灭绝是由外来物体引起的，比如彗星和小行星。

In my children's lifetimes, I believe gorillas; chimpanzees and orangutans will all become extinct in the wild.

我相信，在我孩子们的有生之年，大猩猩、黑猩猩和猩猩会在野外全部灭绝。

In my children's lifetimes, I believe gorillas, chimpanzees and orangutans will all become extinct in the wild.

我相信，在我孩子们的有生这年，大猩猩、黑猩猩和猩猩会在野外全部灭绝。

The island's orangutans are endangered: The population has fallen by more than 50 percent in the past 50 years.

该岛猩猩濒临灭绝：它们的数目在过去50年内减少超过50%。

Congress also declared the Darfur violence genocide in a joint resolution in July.

今年七月，美国国会参众两院也通过联合决议，宣布达尔富尔的暴力冲突是种族灭绝。

WHEN, a few years ago, word came that British bird lovers anxious about the decline of the house sparrow had appointed a sparrow tsar, it seemed that the tsar vogue must have reached its zenith.

几年前，当传闻英国爱鸟者们忧心忡忡于家雀的灭绝而指定了一名&麻雀沙皇&时，似乎&沙皇热&已经达到了顶峰。

The concept of equivalent rotationally rigidity is offered and the formula of rotationally rigidity is obtained.

主要做了如下几个方面的工作：对伸臂位于顶部的单层框架—筒体模型进行分析，提出了等效转动约束的概念和转动约束刚度的表达式。

Male cats normally do not need aftercare with the exception of the night after the anesthetic.

男猫通常不需要善后除了晚上的麻醉。