【正确答案】 B

【答案解析】A species becomes extinct when the last existing member of that species dies. And the extinction of one species' wild population can have knock-on effects, causing further extinctions. These are also called "chains of extinction". All wild populations of living things have many complex intertwining links with other living things around them. Large herbivorous animals such as the hippopotamus have populations of insectivorous birds that feed off the many parasitic insects that grow on the hippo. If the hippos should die out, so too will these groups of birds, leading to further destruction as other species dependent on the birds are affected. Also referred to as a Domino effect, this series of chain reactions is by far the most destructive process that can occur in any ecological community.

【正确答案】 B