题干

做匀速直线运动的甲、乙两物体,它们的速度之比为3:2,通过的路程之比为2:3,则它们所用的时间之比为(   )

A:2:3

B:4:9

C:1:1

D:9:4

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B

同类题2

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    The world seems gloomy(阴沉的)and gray when you're feeling blue. In fact, being down might even affect how you perceive(感知)the color blue. A recent study about color was published in the journal Psychological Science. It shows a direct connection between a person's ability to perceive color and their emotions.

    Psychologists have long known that emotions can affect the way people perceive things. That's in part because chemicals from your brain might affect how you process what you see. “Color is such an important part of our experience,” says lead author Christopher Thorstenson, a psychologist at the university of Rochester, in New York. There's reason, he says, that sad people commonly describe the world as “colorless” and “gray”, and happy people use words like “bright” and “colorful”.

    In the experiment, the researchers randomly assigned people to one of two groups. People in the “sadness” group watched a sad scene from The Lion King. Those in the “amusement' group watched a comedy.

    Everyone was then asked to look at red, yellow, green, and blue patches(斑点)that had been changed to a grayish color. “Some of the patches are pretty difficulty to make out,” Thorstenson admits he says it takes some time to figure out their shade. People were scored on how accurate their color perception was. Then they completed an emotional evaluation.

    The result? Sad people had a hard time seeing the difference between shades along the blue-yellow color axis(色轴). But they did no have problems seeing colors in the red-green spectrum(光谱). Thorstenson says this could be the result of an evolutionary need to see red as a response to anger.

    Thorstenson says these results highlight the possible important of dopamine in sight. Dopamine is a chemical that sends signals to the brain. Researchers are hoping to focus more on dopamine in the future. “We know dopamine affects how we see colors, too,” Thorstenson says “How we feel can really influence how we see the world around us” he says.

同类题3

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    Recently, my mother asked me to drop off some letters at the post office and pick up some stamps for her. Without giving it a thought, I took the letters and purchased her stamps.

    A few days later, she mentioned that one of the letters I had mailed was missing a stamp, and asked me if I had put a stamp on it. She had remembered asking me to put a stamp on it, though I certainly had not heard her. So, unfortunately, it looked like the letter, which was a bill of course, would come back marked "Return to Sender for Insufficient Postage". A few days went by and I returned to the post office to pick up our mail. While I was there, I saw the postmaster and happened to tell him about Mom's letter missing the stamp. I asked him to be on the lookout for it coming back. It was then that he told me his story. "You know," he said, "I immediately saw after you had dropped the mail off that your letter was missing a stamp. I also noticed that it was a bill for a credit card company. I thought to myself that you have always been kind to me and my partner, and I wanted to return the favor. So, to prevent your mother from getting charged a late fee from the credit card company, I took money from our change dish (extra pennies for folks who need one), and purchased a stamp for you."

    When I heard it, I couldn't believe it. What a blessing that was! I thanked him over and over again for putting the stamp on the letter for us. Then, I immediately dumped(倾倒) all the change out of my purse and into the penny dish in order to help others out in the future. When I got home, I was able to tell Mom the good news. This was kindness karma(因果报应) in action, I believe!