题干

把稀硫酸倒在亚硫酸钠粉末上,能使反应的最初速率加快的是

A:增大亚硫酸钠粉末的量。

B:硫酸浓度增大一倍,用量减少到原来的1/2。

C:硫酸浓度不变,用量增大一倍。

D:使反应在较低温度下进行。

上一题 下一题 0.0难度 选择题 更新时间:2019-04-11 09:12:31

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B

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      A glass a day keeps obesity at bay. Wine has always been thought to cause weight gain because of its high sugar content, but new research suggests a glass a day could form part of a diet. Looking at past studies they found that, while heavy drinkers do put on weight, those who drink in moderation can actually lose weight.

    A scientist for the research team at Navarro University in Spain says, “Proper drinking may be more likely to protect against, rather than promote, weight gain.” An official organization reviewed the findings and agreed with most of the conclusions, particularly that present data do not clearly show if proper drinking increases weight.

    Boston University's Dr. Harvey Finkel found that the reasons relating alcohol (酒精) to changes in body weight are not properly understood. His team pointed out the strong protective effects (效果) of proper drinking on the risk of getting conditions like diabetes (糖尿病), which relate to increasing obesity. Some studies suggest that even very fat people may be at lower risk of diabetes if they are moderate drinkers.

    The group says alcohol provides energy that is quickly absorbed into the body and is not stored in fat, and that this process could explain the differences in its effects from those of other foods. They agree that future research should be directed towards assessing the roles of different types of alcoholic drinks, taking drinking patterns into consideration.

    For now there is little evidence that drinking small to moderate amounts of alcohol on a regular basis increases one's risk of becoming too fat. What's more, a study three years ago suggested that a chemical found in grapes and red wine, destroys fat cells.