题干

以下说法中正确的是(   )

A:做单向直线运动的物体,路程与位移的大小一定相等

B:2012年厦门国际马拉松比赛中肯尼亚黑马卡麦斯•皮特以2小时07分37秒获得冠军,这里2小时07分37秒表示时刻

C:瞬时速度的大小通常称为速率

D:速度大小不变的运动就是匀速直线运动

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答案(点此获取答案解析)

A,C

同类题2

阅读下列短文,从每题所给的 A、B、C 和 D 四个选项中,选出最佳选项。

    Time and money are precious resources that managed well can increase happiness. Many people think that money brings happiness while others think that time raises more happiness. As for me, I think people can get greater happiness if they use $ 40 to save time — such as by paying for housework to be done—rather than spending the money on material goods.

    Psychologists say stress over lack of time causes lower happiness and contributes to anxiety. Yet, even the very wealthy are often reluctant to pay people to do the jobs they dislike. But people who spend money to buy themselves more free time are happier — that is they have higher life satisfaction.

    Rising incomes in many countries has led to a new phenomenon. Many people get stressed over the   daily demands on their time. Fewer than a third of individuals spent money to buy themselves time each month. They do things like buying lunches to be delivered to work, paying neighborhood children to run errands(差事)for them, or paying for cleaning. Some experts say time saving compared with material purchases increases happiness by reducing feelings of time stress.

    In fact money can buy time. And it buys time pretty effectively. One reason is because time, relative to money, tends to be filled with personal meaning. Another reason is that time promotes interpersonal connection. Since both personal meaning and social connection are key to happiness, it makes sense how individuals spend their time.

    As a result, can we rethink how we're using time? If we rethink how we spend time, and be more intentional on how we spend time, that may affect the happiness we feel.