When you are in the desert, you have to keep your eyes ____ for snakes that may be hidden in the sand.

Joe's been walking with a spring in his step ever since he found out he was getting a promotion.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions.

There are already many, many people who have passed the landmark age of 100. In fact, there are now so many healthy, elderly people that there's a new term for them: the wellderly. These are people over the age of 80 who have no diseases such as high blood pressure, heart disease or diabetes and have never taken medicines for these conditions.

There have been many scientific studies of communities where a healthy old age is typical. These include places like Calabria in southern Italy and the island of Okinawa in Japan.

The small village of Molochio in Calabria has about 2,000 inhabitants. And of these there are at least eight centenarians. When researchers ask people like this the secret of their long life, the answer is almost always to do with diet and is almost always the same: 'I eat a lot of fruit and vegetables.' 'A little bit, but of everything.’ ‘No smoking, no drinking.’

While in the past scientists have looked at things such as diet and lifestyle for an explanation of long life, these days they are investigating genetics. One such researcher is Eric Topol, who says, "There must be genes that explain why these individuals are protected from the aging process."

The new research into long life looks at groups of people who have a genetic connection. For example, one group of interest lives in Ecuador. In one area of the country there are a number of people with the same genetic condition. It's called Laron syndrome. The condition means that they don't grow to more than about one, but it also seems to give them protection against cancer and diabetes. As a result, they live longer than other people in their families. Meanwhile, on the Hawaiian island of Oahu, there's another group of long-lived men, Japanese-Americans. They have a similar gene to the Laron syndrome group.

Back in Calabria, scientists are trying to work out exactly how much of the longevity is due to genetics and how much to environment. By checking public records going back to the 19th century, researchers have reconstructed the family trees of 202 nonagenarians and centenarians. They concluded that there were genetic factors involved.

Câu 31: Diabetes, heart disease and high blood pressure ____.