题目

一定条件下，反应2NO2(g)        N2O4(g) ΔH<0，在密闭容器中达到平衡。在测定NO2的相对分子质量时，下列条件中，测定结果误差最小的是 A.温度130℃、压强3.03×105Pa     B.温度25℃、压强1.01×105Pa C.温度130℃、压强5.05×105Pa     D.温度0℃、压强5.05×105Pa 答案：C阅读理解。根据短文内容，从短文后的选项中选出能填入空白处的最佳选项，选项中有两项为多余选项。      Is bottled water better for you than tap? Or should you choose vitamin-enriched water? Experts say, skip it all. None of these products is likely to make you any healthier. Below, we look at four major myths about the benefits of drinking water.   1   Experts say there's an easy way to judge. If you are not thirsty, your fluid intake is likely "just right"      Myth No 1: Drink eight glasses each day.      Scientists say there's no clear health benefit of drinking so much water a day.   2   "Nobody really knows," says Dr. Stanley Goldfarb, a kidney expert at the University of Pennsylvania.      Myth No.2: Lots of water equals healthier skin.      The body is already 60 percent water.   3   Adding a few extra glasses of water each day has a limited effect."It's such a tiny part of what's in the body," says Goldfarb." It's very unlikely that one's getting any benefit."      Myth No.3:   4       A more accurate statement may be: Drinking water is a helpful tool for dieters."Water is a great strategy for dieters because it has no calories," says Madeline Fernstrom of the University of Pittsburgh."So you can keep your mouth busy without food and get a sense of satisfaction." But water is not magical, she adds."Other zero-calorie options such as diet sodas are fine, too."      Myth No. 4: It's easy to get dehydrated (脱水的) during a workout.      Dehydration sets in when a person has lost 2 percent of his or her body weight.   5   "It's also obvious that individuals in hot, dry climates have an increased need for water," says Goldfarb. "But for a walk in the park, no water bottle is necessary." ? A. So where does the standard advice come from? B. But it's unclear whether these changes are clinically significant. C. So for a 200-pound man, this means losing 4 pounds of water. D. Drinking extra water leads to weight loss. E. Drink as much water as you can. F. So, if you take a 200-pound man, he's 120 pounds of water. G. But first, how do you know if you're drinking enough water