【正确答案】
D
【答案解析】[听力原文] Vitamin D helps bones and muscles grow strong and healthy. The easiest way to get vitamin D is from sunlight. The ultraviolet rays react with skin cells to produce the vitamin. But many people worry about skin cancer and skin damage from the sun. Also, darker skinned people produce less vitamin D than lighter skinned people. Production also decreases in older people and those living in northern areas that get less sunlight. Not many foods naturally contain vitamin D. Foods with high levels include oily fish such as salmon, tuna and mackerel, and fish liver oils. Boston University researchers reported last year that farmed salmon had a lot less vitamin D than wild salmon. Small amounts of D are found in beef liver, cheese and egg. And some people take dietary supplements containing the vitamin. But most of the D in the American diet comes from foods like milk with the vitamin added. These days, more doctors are testing for vitamin D levels in their patients. But as research continues, some experts worry, that if people take too much D, it might act as a poison. Also, skin doctors warn people to be careful with sun exposure. How much vitamin D does a healthy person need? Nutrition experts who advise the American government set the current recommendations in 1997. The daily amount is two hundred international units from birth through age 50. Then it rises to four hundred international units through age seventy, and six hundred for those seventy-one and older. But some groups say these amounts are not high enough. According to the speaker, what is the easiest way to get Vitamin D? 短文一开始就提到了the easiest way to get vitamin D，即“从阳光中获取维生素D”。故选D。 本题符合短文听力“语义强调处出题”的规律，the easiest后的内容需重点留意。
【正确答案】
B
【答案解析】[听力原文] According to the speaker, who produces the most Vitamin D? 短文提到，深色皮肤的人比浅色皮肤的人产生的维生素D要少，老年人和那些居住在北部地区获得阳光较少的人产生的维生素也较少。故选B。 听音时应抓住重点，注意四者的对比关系，以及问题问的是produces the most Vitamin D，切勿粗心弄错。另外，A和B意思相对，这样的选项中通常其一就是正确答案。