根据下列文章,请回答 16～22 题。 Osteoporosis and Men Mention the word osteoporosis in the manly world of testosterone(睾丸素)，professional basketball and the XFL(美国最新的职业足球联合会)，and you’re likely to get a wave of the hand and a dismissive(轻蔑的)“That’s a woman’s disease．”Not S0．More than 2 million American men have been found to have the thinning bones and skeletal(骨骼的)weakness of osteoporosis(骨质疏松症)，and an additional 3 million are at an increased risk of developing them． It’s true that osteoporosis strikes women with much greater frequency than men-in some studies as much as four to six times as often．But that’s no reason to brush it off as“their’ disease．It's a mere stroke of gender luck that men’s bones tend to grow larger。stronger and denser．Also paying dividends are those spots that boys(and，increasingly，girls)play as children—running up and down basketball coups，soccer and baseball fields．As it happens．physical activity is one of the more important ways to increase bone density and protect bone health． But even the most active men cannot ignore certain facts of life．All of US build up Our bones during the first three decades of life，typically reaching peak bone mass in the early 30s．Around the age of 35，we begin gradually to lose some of this bone mass．Women ultimately give up between 30％．Though mass loss in men is lower, it still makes US vulnerable to back pains and bone fractures．In fact，this year alone American men will suffer as many as half a million osteoporosis-related breaks，mostly in the spine，hip and wrist．These are not only painful；thousands die each year from fracture—related complications． For many of US，however, there’s still time．Of all the side effects of aging，osteoporosis is one of the more preventable．through diet，exercise and changes in lifestyle．The two key nutritional substances for bone health are calcium(钙)。which makes bones stronger, and vitamin D，which helps the body absorb the calcium． Exercising is also important。with emphasis on weight-bearing activities in which bones and muscles work against gravity．Lifting weights and working out on resistance machines can help preserve bone density． Be careful about what’s in your medicine cabinet．Prolonged use of some medications，such as steroids(类固醇)，can weaken your bones．Smoking and drinking are both bad for bones。as is prolonged weightlessness，for anybody who plans to work on the space station． 第 16 题 Men are justified in thinking that osteoporosis is a woman’s disease．