[04:12.15]Scientists say the return of wolves to Yellowstone National Park in the American state of Wyoming has boosted the diet of a rival predator, the grizzly bear.
[04:22.37]Our science reporter Helen Briggs explains why.
[04:25.80]Wolves returned to Yellowstone nearly 20 years ago, put back into the wild to prey on the growing elk population.
[04:33.81]Elk were overgrazing the grassland, causing damage to the precious eco-system.
[04:39.21]Now scientists say the wolves have had benefits for another predator, the grizzly bear.
[04:44.21]Trees and shrubs are springing back up, bearing nutritious berries, a valuable food source for the grizzly bear.
[04:51.60]Wild fruits are a key part of the bear’s diet as it gains weight before hibernating.
[04:57.20]Helen Briggs
[04:58.47]BBC News
第三页:词汇解析
abuse">abuse
难度:4星核心词汇,属常用3000词
英汉解释
n.滥用;恶习
vt.滥用;辱骂;虐待
参考例句
用作名词 (n.)
The government has set up a working party to look into the problem of drug
abuse">abuse
.
政府已成立工作组调查滥用毒品问题。
用作及物动词 (vt.)
I don't consider it good for a person to be afraid of being