题干

如图,小物体m与圆盘保持相对静止,随盘一起做匀速圆周运动,则物体的受力情况错误的是:(   ) 
 

A:受重力、支持力、静摩擦力和向心力的作用

B:摩擦力的方向始终指向圆心O

C:重力和支持力是一对平衡力

D:摩擦力是使物体做匀速圆周运动的向心力

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A

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    Traveling for business or pleasure can easily damage your health. It's easy to fail into the trap of high caloric meals and little exercise.____

    Keep a dictionary on hand

    If you are traveling somewhere with a different language, pack a dictionary and keep it close to help you negotiate(商议)the menu and make healthy food choices.____Look up the words that you don't understand to help you learn about cooking methods and ingredients(材料)so that you can choose healthy food.

    ____

    The more you can research before your trip, the easier it will be to keep a healthy lifestyle while traveling. To stay on track with your food, try to find a nearby grocery store or healthy food store, look up a couple of well rated restaurants that offer some healthy choices, and try to stay somewhere with a fridge or kitchen.

    Walk every day.

    Exploring your destination(目的地)on foot is an amazing way to take some exercise while traveling. Walk through the nature to enjoy its beautiful scenery, listen to the sound of nature and take some wonderful pictures.____

    Rent a bike.

    Cover more ground while burning calories by renting a bike. Many major cities have bike-sharing programs, or you could contact a local bike store to ask about bike rentals.____If you have an open schedule, you could even research bike tours, which are a great way to cover a long distance in a short period of time.

A. Avoid junk food and deep fried food.

B. Research the food and store some upon arrival.

C. Take a bike map of the city, research day trips and get exploring.

D. If you are exercising while traveling, make sure to take in extra water.

E. Here are some healthy travel tips which will keep you in good health.

F. You can't avoid deep fried food if you don't know that they're in there!

G. This is also a great way to find hidden attractions that aren't in the travel guides.