题目内容：

    Many cultures around the world have a grain that is not grown or even known outside its home area. Now, a staple grain native to Ethiopia, teff, is appearing on grocery shelves in America.

Teff has been an important part of the Ethiopian diet for thousands of years. Like rice and wheat, it is a cereal grass. Teff is known for its fine grain and used mainly to make flour. Teff flour is the key ingredient in injera, the large, spongy pancakes that make up a large portion of the Ethiopian diet.

Teff was introduced to the United States by a man named Wayne Carlson, who learned about teff while doing public health work in Africa in the mid-1970s. "I came to know teff because I was eating it all the time and hosted by teff farmers. " he said. In the late 70s, Carlson returned to the U. S. , married and settled in southwest Idaho. Then he came up with an idea to introduce teff grass to his home state. " Geologically, it is very similar to Ethiopia."

Wayne and his wife Elisabeth are not farmers, nor do they want to be. So they convinced actual farmers in Idaho to grow teff on contract for them. The Carlsons milled it themselves.

Wayne went through the Washington, D. C. telephone book and looked for the names that were Ethiopian. And that is how the business slowly grew. Over time, the Teff Company has outgrown four different mills.

Rich Roseberg is a food researcher at Oregon State University. He says teff production has exploded over the past decade in the U. S. He says most teff grown in the U. S. is fed to farm animals. In Idaho, however, where the Carlsons are based, Roseberg believes more of the teff production is for human food. Teff contains lots of calcium, iron, protein and fiber. Roseberg credits Wayne Carlson for being ahead of his time.

1.How do the Ethiopians mainly use teff?

A.By eating the cereal grass. B.By using the flour made from it.

C.By adding the plant into injera. D.By mixing it with rice and wheat.

2.According to Wayne, why is it possible for teff to grow well in Idaho?

A.Idaho is located close to Ethiopia.

B.Teff is easy to survive on its own.

C.Idaho has geographic features similar to Ethiopia.

D.Teff was originally introduced to Ethiopia from Idaho.

3.What can we infer from Paragraph 5?

A.Wayne's teff did not sell well at first.

B.Wayne's teff was sold only to Ethiopians.

C.Wayne sent teff to his Ethiopian friends.

D.Wayne lost control of his Teff Company.

4.What is Rich Roseberg's attitude to Wayne introducing teff into America?

A.Worried. B.Disapproving.

C.Favorable. D.Pessimistic.