1 . 阅读下面短文, 在空白处填入1个适当的单词或括号内单词的正确形式。

The ginkgo (银杏) tree is thought to be one of the oldest living trees,     1     (date) back to more than 290 million years ago. It is native     2     China, Japan and Korea, but it is also now grown in Europe and the United States. The earliest records of ginkgoes are found in Chinese herbology literature such as Compendium of Materia Medica.

Ginkgoes are large trees,     3     (normal) reaching a height of 20 — 35 meters, with some in China being over 50 meters. The adult tree has a large crown and long branches, and it is usually deep-rooted and resistant to wind and snow damage. With a combination of     4     (resistant) to diseases and insects, some of the trees     5     (claim) to be more than 2,500 years old.

With fan-shaped leaves, ginkgoes are green both on the top and bottom. But during autumn, they turn bright yellow and then fall, which make up     6     beautiful scene. Ginkgoes come in two sexes, with some trees being female     7     others male. The fruit has a soft, fleshy and yellow-brown outer layer     8     is attractive in appearance.

Because ginkgoes     9     (be) around for so long, people have used them for many purposes. It’s commonly used for memory and thought problems, vision problems and many other conditions, but there is no good scientific evidence     10     (support) most of these uses.

2 . Antioxidants (抗氧化剂) are found naturally inn plants like blueberries, blackberries, and red cabbage. Scientists believe antioxidants may help prevent heart disease and help fight against diseases like diabetes. But tomatoes naturally only have a small amount of antioxidants in them.

British scientist Cathie Martin wanted to see if she could create tomatoes with lots of antioxidants by changing the DNA of a tomato plant.

A plant developed from specially created DNA is known as a GMO, or “genetically modified organism”. For hundreds of years, farmers have created new kinds of plants by mixing existing plants together using natural methods. GMO plants are different because the plants’ DNA has been changed by scientists. Scientists who do this usually think they’re improving the plants in some way.

After working on developing purple tomatoes for years, Dr. Martin’s experiment worked. Soon her plants were producing small purple tomatoes. Though the color is unusual, what’s really special about the tomatoes is that they have very high levels of antioxidants. Even better, the tomatoes remained fresh almost twice as long as normal tomatoes. Soon, Dr. Martin and other scientists created a company to promote the tomatoes.

The company tested its tomatoes on mice that were likely to get cancer. The mice who were fed the purple tomatoes lived about 30% longer than the mice who were fed normal tomatoes. Though that’s good news, experiments on mice don’t always predict what effects on humans will be like.

And GMO products weren’t popular with customers. Many people were scared by the idea that the foods weren’t “natural”. There are still questions about the effects of GMO crops on the environment and other plants, but most scientists agree that food from GMO crops is safe to eat.

On September 7, the government approved a GMO plant designed to target human health. Dr. Martin and her company plan to introduce the tomatoes at farmers’ markets across the US in 2023. They also hope to sell the seeds to people who want to grow their own.

1. What is the function of paragraph 1?

A．To define a concept.

B．To bring in the topic of the text.

C．To add background information.

D．To introduce the benefits of antioxidants.

2. What makes purple tomatoes really special?

A．Their medical value.	B．Their delicious flavor.
C．Their proper size.	D．Their pleasant color.

3. Why are GMO foods refused by people?

A．They are expensive to buy.

B．They are intended for animals.

C．They are thought to be harmful.

D．Their appearance isn’t appealing.

4. What is the government’s attitude towards GMO crops?

A．Opposed.

B．Unclear.

C．Positive.

D．Concemed.