Question

Energy goes from one plant or animal to another. A food chain shows how this energy moves. Each time an animal gets eaten, its energy is passed onto the animal that eats it. The food chain is very important because it keeps the balance of nature. If one part of the food chain disappears, it can affect all the other plants and animals. Any threat to the food chain is a threat to the environment’s biodiversit(生物多样性). The food chain helps keep animal populations in balance. However, if something happens to increase or decrease one of the links in the food chain, that balance is broken. If one animal becomes endangered, it puts all the animals above it at risk.

Some of the threats are natural, such as wildfires, hurricanes, tornados, floods and so on. But the biggest threats to the food chain come from you and me. These threats include overhunting, overfishing, logging, farming, development, pollution, etc. The food chain is endangered anywhere humans have had an effect on the natural environment.

A recent study shows that the overfishing of large sharks is damaging the food chain along the US Atlantic coast. Canadian and American scientists say sharks are being killed in great numbers for their meat and fins(鳍). Now, not enough sharks are around to eat the cownose(牛鼻) ray. The ray’s population has increased and they have eaten up the shellfish to the point where it has hurt commercial(商业的) fishing.

Many of us disturb the natural environment in our own backyards. It’s up to us to take care of the environment and try not to disrupt the natural food chain. If we don’t act responsibly, animals will start disappearing.

1.What can we learn from Paragraph 1?

A. The food chain is not easy to be broken.

B. The energy of an animal usually disappears when it dies.

C. Increasing the links will not break the balance of nature.

D. Breaking the food chain is bad for the biodiversity of the environment.

2.The study mentioned in Paragraph 3 proves that             .

A. human activities can be a big threat to the food chain

B. we are all responsible for the breaking of the food chain

C. natural disasters are hard to break the food chain

D. hunting large sharks for meat is beneficial

3.We can infer that the writer wrote this passage mainly to            .

A. explain what the food chain is

B. tell us something interesting about Nature

C. suggest that we stop eating meat to save animals

D. suggest that we not disrupt the natural food chain

Answer

1.D

2.A

3.D

【解析】

试题分析：文章主要讲的是食物链的重要作用和食物链面临的严重威胁。食物链的存在对维持自然界的生态平衡有着重要的作用，然而，食物链正面临着很多威胁。一些威胁来自自然界本身，像野火、飓风、洪水等。但是，最大的威胁来自人类活动。

1.The food chain is very important because it keeps the balance of nature....Any threat to the food chain is a threat to the environment’s biodiversit(生物多样性).”可知，食物链的存在对维持大自然生态平衡和生物多样性有着重要的作用，如果食物链遭到破坏，食物链上的所有动植物都会受到影响，故选D。

2.The food chain is endangered anywhere humans have had an effect on the natural environment.”可知，人类的过度捕猎、过度捕捞和过度砍伐等行为已经给食物链带来了很大的威胁，第三段列举的是过度捕杀鲨鱼的例子，以此来说明人类活动对食物链产生的威胁，故选A。

3.It’s up to us to take care of the environment and try not to disrupt the natural food chain. If we don’t act responsibly, animals will start disappearing.”可知，人们应该自觉地保护环境，不去破坏自然界存在的食物链。说明作者写这篇文章是在建议读者不要破坏食物链的自然平衡，爱护我们的环境，故选D。

考点：环保类短文阅读