Read the passages and answer the questions.
In an effort to save Australia's dying koalas, scientists are hoping to find out why they eat the leaves of only some eucalyptus trees.
The population of Australia's koalas has been decreasing in this century and could vanish by the end of the decade, the Australian Koala Foundation says.
A three-year scientific project was launched last year aiming to find out what the key chemicals are that allow only some types of leaves to be eaten by koalas.
Bill Foley, biologist at James Cook University, said koalas eat only a few types of eucalyptus leaves.
If we are going to change the forests for the koalas, or rehabilitate sick or injured animals, then we need to know what makes a leaf good to eat," he said.
"We expect that we will be able to choose or breed trees that improve the nutrition of koalas and also identify areas that are suitable for the long-term survival of koala populations," Mr. Foley said.
Koala numbers in the wild have been decreasing quickly. The Australian Koala Foundation says there are just 50,000 to 80,000 wild koalas left, and has warned they could be extinct by the turn of the century.
(Bangkok Post Student Weekly; February 5, 1996)