题目内容：

Imagine putting a seed in a freezer,waiting 30,000 years,and then taking the seed out and planting it. Do you think a flower would grow?

Amazingly, scientists have just managed to do something very similar. They found the fruit of an ancient plant that had been frozen underground in Siberia—a region covering central and eastern Russia—for about 31,800 years. Using pieces of the fruit,the scientists grew plants in a lab. The new blooms have delicate white petals. They are also the oldest flowering plants that researchers have ever revived from a deep freeze.

“This is like regenerating a dinosaur from tissues of an ancient egg,’’said Jane Shen-Miller,a biologist of University of California,Los Angeles.

The plant has a long history. Back when mammoths and woolly rhinoceroses walked on the land, an Arctic ground squirrel buried seeds and fruits in an underground chamber near the Kolyma River in northeastern Siberia. The ground became pennafrost, a layer of soil that stays frozen for a long time.

Recently, Russian scientists dug out the old squirrel hole and found the plant remains 38 meters below the surface. Back at the lab, the team fed nutrients to tissue from three of the fruits to grow shoots. Then the scientists transferred the shoots to pots filled with soil. The plants produced seeds that could be used to grow even more of them.

It’s important for scientists to know that plant tissues can still be revived after being frozen for a long time. That’s because many researchers are trying to preserve the seeds of modem plants by freezing them and then storing them in giant lockers at various spots around the globe. One such endeavor,an underground facility in Norway,is called the Svalbard Global Seed Vault. It stores hundreds of thousands of frozen seeds. If a plant ever goes extinct, scientists could bring it back by taking its seeds from the Svalbard or other storage lockers.

“No one knows how long they are able to live for,but freezing is basically the format for many plant conservation attempts nowadays,’’Jane Shen-Miller said. It’s a good thing that at least some plants are tough enough to survive in the experience.

1.Which of the following was NOT used to recreate the ancient plant?

A. Modem nutrients.

B. Parts of the fruits.

C. Its frozen seeds.

D. Plant pots with soil.

2.Why are scientists interested in this discovery?

A. It helps them learn how plant life has changed in the past 30,000 years.

B. It can help guide future efforts to protect endangered plants’ life.

C. It can provide directions for where to look for other ancient plants.

D. It proves that all plant life can survive for thousands of years when frozen.

3.The underlined word "they", in the final paragraph refers to             .

A. plants

B. seeds

C. scientists

D. storage lockers

4.The purpose of the passage is to            .

A. discuss a plant conservation effort

B. introduce some ancient plants

C. outline some causes of global warming

D. describe a scientific research project