根据以下资料，回答下列各题。 Thinner isn’t always better. A number of studies have ___1___ that normal-weight people are in fact at higher risk of some diseases compared to those who are overweight. And there are health conditions for which being overweight is actually ___2___. For example, heavier women are less likely to develop calcium deficiency than thin women. ___3___ among the elderly, being somewhat overweight is often an ___4___ of good health. Of even greater ___5___ is the fact that obesity turns out to be very difficult to define. It is often defined ___6___ body mass index, or BMI. BMI ___7__ body mass divided by the square of height. An adult with a BMI of 18 to 25 is often considered to be normal weight. Between 25 and 30 is overweight. And over 30 is considered obese. Obesity, ___8___,can be divided into moderately obese, severely obese, and very severely obese. While such numerical standards seem ___9___ , they are not. Obesity is probably less a matter of weight than body fat. Some people with a high BMI are in fact extremely fit, ___10___ others with a low BMI may be in poor ___11___ .For example, many collegiate and professional football players ___12___ as obese, though their percentage body fat is low. Conversely, someone with a small frame. may have high body fat but a ___13___ BMI. Today we have a(an) ___14___ to label obesity as a disgrace.The overweight are sometimes___15___ in the media with their faces covered. Stereotypes ___16___ with obesity include laziness, lack of will power,and lower prospects for success.Teachers,employers,and health professionals have been shown to harbor biases against the obese. ___17___very young children tend to look down on the overweight, and teasing about body build has long been a problem in schools. Negative attitudes toward obesity,____18____in health concerns,have stimulated a number of anti-obesity____19____.My own hospital system has banned sugary drinks from its facilities. Many employers have instituted weight loss and fitness initiatives.Michelle Obama has launched a high-visibility campaign____20____childhood obesity,even claiming that it represents our greatest national security threat. 请在第__1__处填上正确答案。

A.denied

B.conduced

C.doubled

D.ensured

请帮忙给出正确答案和分析，谢谢！