题干

半径为rRrR)的光滑半圆形槽,其圆心均在同一水平面上,如图所示,质量相等的两物体分别自半圆形槽左边缘的最高点无初速地释放,在下滑过程中两物体               (  )

A:机械能均逐渐减小

B:经最低点时动能相等

C:机械能总是相等的

D:两球在最低点加速度大小不等

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C

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    The key to losing weight is to understand what really motivates you. Have you ever been excited about losing a few pounds?____ And to help you keep your weight under control, you need some coping strategies.

    Ask questions. When you're researching different dieting products and plans or even talking to a doctor about diets, ask as many questions as you can.____Ask questions like: Do I have to purchase special meals or supplements? Does the program include a part to help me maintain my weight loss?

    Get real.____ Don't burden yourself with unrealistic expectations. Remember, large amounts of weight loss are not realistic and are most likely not safe or healthy. Talk with your health care professional to determine a healthy weight goal.

    ____To maintain your weight, you must balance your intake of calories with the energy you burn. Just 30 minutes of fast walking in most days can take about 10 pounds off your weight each year.

    Weigh yourself weekly. It's important to track your weight on any diet or weight loss plan, but don't get on the scale every day. Weighing daily won't show you the big picture.____

A. Stay balanced.

B. Once a week is fine.

C. Stick with your healthy eating plan.

D. Losing one to two pounds a week is a realistic goal.

E. Being well informed will help you choose the best diet for you.

F. Regular weight check-ins will show you your progress over time.

G. If so, you must find a way to turn that excitement into determination.