D
We all know that green vegetables are healthy, but what about other foods of different colours? It is good for you to have different colours in your diet(饮食). For example, you can eat red food like strawberries, yellow food like pears, and orange food like carrots. But what about the blue food?
A food company puts the colour blue in its bags of sweets. Children like the colour blue, so are the blue sweets popular(受欢迎的)? The food company is surprised to find that they aren't popular at all. Children still like red, green, brown, yellow and orange sweets.
How many blue fruits or vegetables do you know? There are few blue foods in nature—it isn't a common food colour. So, we don't think blue food is healthy or safe to eat. Maybe this is why we don't often use blue food colouring for drinks, cakes and other food.
Some people say we eat with our eyes. The idea is that we need to like the looks of the food before we try it. I want to test(测试) this idea, so I ask some friends to have a very special lunch. My husband and I make some bread and put blue colouring in it. But no one eats it.
So will we ever see blue food on our dishes? The answer may be “no”, at least(至少) in countries like the UK and the US.
1. What is good for you in your diet?

2. What does the underlined word “they” refer to (指代)?

3. Why do we seldom use blue food colouring for drinks, cakes and other food?

4. How does the writer test the idea in Paragraph 4?

5. In which countries won't we see blue food on people's dishes?

1. Having different colours in my diet.
2. Blue sweets.
3. Because we don't think blue food is healthy or safe to eat.
4. She asks some friends to have a very special lunch.
5. The UK and the US.

E
Helping Birds in a Changing World
Do you think birds are interesting? Do you like spending time outside? Do you care about wildlife and nature? If you answer "yes" to these questions, you may think about becoming a bird biologist(生物学家).
Bird biologists are a kind of scientist and they study birds. For example, some kinds of birds are in danger because they travel a long way in the migration(迁徙). In North America, birds travel to different places in the summer and in the winter. Bird biologists start to study how and where birds get hurt on the way and try to help them. But that's not all bird biologists do!
Beth Flint is a bird biologist in a wildlife refuge(保护区) near Hawaii. She tracks(追踪) all the different kinds of seabirds in the refuge. She reads science studies about all the animals in the wildlife refuge, and makes plans to help save them. She gives lessons about the wildlife to workers in the refuge, too.
As a bird biologist, Dr Flint studies many different fields. She learns about biology, zoology(the study of animals), and botany(the study of plants). Her interest in seabirds started when she was a student. She saw a photo of a special bird in a tree and wanted to learn more about them.
You never know where your interests may lead(引领) you. They may lead you to become a wildlife scientist!
1. What are bird biologists?

2. Why are some kinds of birds in danger?

3. What does Beth Flint do for workers in the refuge?

4. How many different fields does Beth Flint study as a bird biologist?

5. What does the underlined word "They" refer to?

1. They are a kind of scientist and they study birds.
2. Because they travel a long way in the migration.
3. She gives lessons about the wildlife to them.
4. Three. / 3.
5. The interests.