题干

下列有关科学实验与方法的叙述正确的是(   )

A:恩格尔曼用同位素标记法证明叶绿体是光合作用的场所

B:证明DNA进行半保留复制的实验应用了放射性同位素示踪技术

C:研磨苹果获取还原性糖、研磨剪碎的绿叶提取色素都要添加SiO2和CaCO3粉末

D:艾弗里采用放射性同位素标记法,证明了遗传物质是DNA

上一题 下一题 0.0难度 选择题 更新时间:2018-05-30 07:22:00

答案(点此获取答案解析)

B

同类题3

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。

    Eating healthy 100% of the time can seem like a near impossible goal. But along with consistent exercise, healthy eating will make you feel better, give you more energy, and help you perform better in your workouts. ____

    Here are some tricks to make healthy eating easy:

    ● ____

    Protein is what keeps you full, fuels your muscles, and helps you keep a strong and slim figure. Starting your day out with around 30 grams of protein will not only help get you through the morning without feeling hunger pains, it will also help you get less desires for sugar and carbs(碳水化合物)later in the day.

    ●Make veggies a main part of every meal

    ____ You'll find that you might actually start to like vegetables, and your body will start to want them because of how good they make you feel after eating them.

    ●Eat whole foods whenever possible

    Simply focus on avoiding processed foods and include as many whole foods as possible in your diet. ____ But once you discover how food is supposed to taste, eating healthy will become much more natural to you.

    ●Don't deny yourself your favorite foods

    ____ Because it'll cause you to feel bitter, more often leading to a binge(大吃)eating session. So if you're working out and keeping active on a regular basis, allowing yourself a few small treats every once in a while will not only make you happier, it will also make it more likely that you'll stick with healthy eating in the long run.

A. So want exactly are whole foods?

B. It may take a little to get used to

C. And it doesn't have to be that difficult

D. Limit them, but don't cut them out altogether

E. There are so many good ones to choose from

F. Eat a protein-packed breakfast every morning

G. Make them a main part of every meal, at least two thirds of your plate as often as possible