单选题 Questions 1 to 10 are based on the following passage.

More than half of American adults____1____vitamin pills.

Data from the National Health and Nutri-tion Examination Survey (NHANES)____2____a trend away from all-in-one multivitamins and toward specific supplements—especially fish oil and vitamin D.Most of this is self-prescribed.

According to an analysis of the NHANES data, less than a quarter of supplements are taken at the___3_____o f a health professional. 

Most of this nutritional enthusiasm does no____4____, and for those with inadequate diets or special health concerns, supplements can do a world of good.But it is wise to keep in mind that doses that far exceed the recommended dietary allowances set by the Institute of Medicine can be hazardous.

A reminder comes from a recent study linking____5____B vitamins to a heightened risk of hip fracture. 

The study combed through the vitamin habits of nearly 76,000 postmenopausal women____6____in the decades-long Nurses' Health Study.

Lo and behold, those who took high doses of vitamin B6 (35 milligrams or more daily), together with B12 (20 micrograms or more), had a nearly 50 per-cent____7____risk of fracturing their hip than those taking low doses or none.High doses of B6 alone also raised the risk.

The study____8____similar findings in a large Norwegian trial that looked at whether these vitamins and folic acid could reduce heart attacks and strokes in patients with narrowed blood vessels.

Alas, they did not, and to the great____9____ of researchers, high doses were linked to hip frac-tures.

Taken together, “the results are quite____10____”says Haakon Meyer,a professor of epidemiology and preventive medicine at the University of Oslo.

空白处6应填无
【正确答案】 B
【答案解析】空格所在句结构完整,分析可知此处填入的词作postmenopausal women的后置定语,选项中动名词participating,misleading和convincing可作后置定语。根据句意可知,这项研究梳理了近76 000名绝经妇女服用维生素的习惯,这些妇女________了长达数十年的护士健康研究,participating意为“参与,参加”,符合题意。故本题选B。