题目内容：

Cancer researchers urged people on Wednesday to take more vitamin D to lower risk of cancer, saying studies showed a clear link. “Our suggestion is for people to increase their intake, through diet or a vitamin supplement. ” Dr.Cedric Garland said in a telephone interview.

Garland’s research team reviewed 63 studies, including several large long-term ones, on the relationship between vitamin D and certain types of cancer worldwide between 1966 and 2004.

“There’s nothing that has this ability to prevent cancer,” he said, urging governments and public health officials to do more to fortify foods with vitamin D. Garland is part of a University of California at San Diego Moores Cancer Center team that published its findings this week online in the American Journal of Public Health. Vitamin D is found in milk, as well as in some fortified orange juice, yogurt and cheeses, usually at around 100 international units(IU) a serving. People might want to consider a vitamin supplement to raise their intake to 1000 IUs per day, Garland said, adding that it was well within the safety guidelines established by the National Academy of Sciences.

The authors said that taking more vitamin D could be especially important for people living in northern areas, which receive less vitamin D from sunshine.

African Americans, who don’t produce as much of the vitamin because of their skin colour, could also benefit significantly from a higher intake, the authors said.

1.According to the passage, people are advised to take more Vitamin D because ________.

A. it is nutritious

B. it can’t harm people’s health

C. it can lower cancer risk

D. it is not taken enough every day

2.Who can Garland probably be?

A. A health researcher.

B. A doctor.

C. A scientist.

D. A public health official.

3.Which of the following food can lower people’s chance of getting cancer?

A. Milk.

B. Fortified orange juice.

C. Fortified yogurt.

D. All of the above.

4.People from which area should take more Vitamin D according to the passage?

A. Asian people.B. African people.

C. American people.D. European people.