1 . Many animals and plants are endangered in the world today. These endangered species are threatened with becoming extinct, meaning they will no longer exist on Earth. Examples include the Cuban Macaw and the Sri Lankan Legume Tree. Illegal hunting, and collecting of the Macaw bird for pets, led to its extinction. While the main reason the native Sri Lankan Legume Tree went extinct was due to habitat loss from development in the 20th century. The main cause for animals and plants disappearing is often a damage to the food chain due to hunting, habitat loss or even the introduction of new species.
Every living thing from one- celled animals to a blue whale needs to eat. Nature is connected and controlled by many weak food chains. A food chain describes who eats whom in a habitat. When one of the links in a food chain is no longer present—for example, a species goes extinct—the food chain breaks and sometimes this can cause other animals to disappear and the whole system can become imbalanced or even collapsed.
Humans can have horrible effects on food chains. When people first explored the world, they took animal and plant species from their home countries to the places they explored and settled in. They did not realize the consequences of introducing invasive species. By doing so, they were damaging the natural food chains of the areas they explored.
Nowadays there are strict rules controlling the movement of animals and plants between countries. But some parts of the world are still experiencing problems with invasive species introduced hundreds of years ago.
With rising awareness of how we affect the natural environment, hopefully we can learn to protect these food chains and help them to thrive. Otherwise the continued loss of species will eventually mean our own extinction.
1. Which is the main reason for Cuban Macaw’s extinction?
| A．Illegal hunting. | B．Food chain damage. |
| C．Invasive species. | D．Habitat loss. |
2. What do we know about a food chain in paragraph 2?
| A．It only affects one-celled animals. | B．It decides the balance of the whole system. |
| C．It is always broken by invasive species. | D．It breaks after nearly ten species disappear. |
3. How do humans seriously affect food chains?
| A．By hunting endangered animals. | B．By exploring new places. |
| C．By polluting natural environment. | D．By introducing invasive species. |
4. Which is the most suitable title for the text?
| A．Disappearance of Endangered Species | B．Effect of Illegal Hunting on a Habitat |
| C．The Link between Food Chains and Extinction | D．Damage of Invasive Species |
