VOA慢速英语:Changing Arctic Conditions Threaten Polar Bears

短语讲解：

1. But a team of researchers has found that the animals’ ice habitat is warming up, and shrinking.

warm up 使热; 变热
例句：Your feet will soon warm up once you get indoors.
你一进屋,脚就会很快暖和起来。

2. They captured more than 20 polar bears, and tested their blood.

more than 多于
例句：Margaret needed support more than ever.
玛格丽特比以往更需要关心。

3. Other studies had suggested that the bears could deal with a lack of food in the summer by reducing their activity -- like the animals do when they hibernate in the winter.

a lack of 缺乏
例句：Hard work can often make up for a lack of intelligence.
勤奋工作往往可以弥补智力的不足。

4. We found that polar bears -- like their nearest relatives the brown bears -- are incapable of reducing their metabolic rate to the level that we see during winter hibernation.

be incapable of 不能
例句：She is incapable of constructing a grammatical sentence.
她造不出一句语法通顺的句子。