The Olympic flame:

The Olympic flame is a symbol carried over from the ancient Olympics, where a flame burned at the altar (神坛) of Zeus throughout competition. It was finally reintroduced at the 1924 Amsterdam Games, and again burned in 1932.

Carl Diem, chairman of the organizing committee for the 1936 Berlin Games, proposed that the flame be lit in Greece and transported to Berlin via a torch relay. The idea was adopted, and continued at every Olympic Games since 1952.

The flame is lit at the ancient site of Olympia by the natural rays of the sun reflected off a curved mirror. It is lit at a ceremony by women dressed in robes resembling those worn in ancient times, who then pass it to the first relay runner.

Olympic motto:

“Citius, altius, fortius” is a Latin phrase meaning “swifter, higher, stronger”, which Baron de Coubertin borrowed from Father Henri Martin Dideon of Paris. Dideon was headmaster of Arcueil College, and used the phrase to describe the athletic achievements of students at the school. He had previously been at the Albert Le Grand school, where the Latin words were carved in stone above the main entrance.

Olympic oath (宣誓)

“In the name of all competitors, I promise that we shall take part in these Olympic Games, respecting and abiding by the rules that govern them, in the true spirit of sportsmanship, for the glory of sport and the honour of our teams.”

Written by Baron de Coubertin, the oath is taken by an athlete from the host nation while holding a comer of the Olympic flag. The athletes’ oath was first taken by Belgian fencer Victor Boin at the 1920 Antwerp Games. A judge from the host country also speaks the oath, with slightly different wording.

While many people aren’t getting enough calcium (钙), new research cautions that some people may have the opposite problem: they could be getting too much. Americans spend more than $1 billion a year on calcium supplements in hopes of delaying osteoporosis, a kind of bone disease that disables many elderly women and some men. Yet recent studies link calcium supplements to a higher risk of heart attacks. Last month, the U.S. Preventive Services Task Force issued a draft recommendation against taking calcium and vitamin D，saying there wasn’t enough evidence of benefit to justify the risk.

For generations of Americans who grew up encouraged to drink milk to maintain strong bones, the reports raised troubling questions: Is calcium not so important after all? Are the supplements unsafe? And how much is too much? “It’s gotten very confusing but it doesn’t need to be,” says Ethel Siris, director of the Toni Stabile Osteoporosis Center in New York. How much calcium people need varies by age and gender. “Adults generally need 1,000 mg daily, rising to 1,200 mg for women over 50 and men over 70, according to guidelines issued in 2010. Children need 1,300 mg daily during the peak growing years of 9 to 18.”

People also need sufficient levels of vitamin D to absorb the calcium. The IOM recommends 600 international units a day for most adults, and 800 daily after age 70，although many physicians recommend more. It is difficult to take in that much vitamin D from food sources, so experts say many people should take vitamin D in supplement form.

Getting adequate calcium from food is easier. For example, 8 ounces of milk or 6 ounces of yogurt has 300 mg of calcium, and one cup of spinach has 270 mg.

But studies linking calcium supplements to heart attack have made experts more cautious of excess calcium than before. A study of 24,000 Germans published in the journal Heart last month, found that those who got their calcium exclusively from supplements were more than twice as likely to have a heart attack as those who took no supplements.

Exactly how calcium supplements might contribute to heart attacks baffles experts. “Nobody has associated the calcium in your bloodstream with calcification(钙化)in your arteries(动脉),” says Nieca Goldberg, medical director of the Joan H. Tisch Center. Still, she says she now urges patients get their recommended calcium from food rather than from supplements to avoid possible problems.

Osteoporosis experts also urge patients not to take more than the recommended amount of calcium. “People should definitely stop taking two big calcium supplements a day,” says Dr. Dawson-Hughes. Even if the risks remain unclear, taking more than the body can absorb doesn’t benefit bones,” so it’s not worth any risk.” She adds.