题干

如图所示用镊子夹豆子时,镊子相当于____杠杆(选填“省力”、“等臂”或“费力”).松开镊子,豆子会加速下落,说明力可以改变物体的____,在此过程中,豆子的重力势能____(选填“变大”、“不变”或“变小”).

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答案(点此获取答案解析)

费力,运动状态,变小

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    Millions of Chinese have been playing a mobile game called Travel Frog recently. You play as the “mother” of a frog who lives alone and enjoys traveling. You need to prepare food and tools for his trips. The frog will send you postcards while he is away.

    The game's popularity may have something to do with how lonely people are these days, according to the Xinhua News Agency. Many players have said that the lonely frog is just like them. But playing with the frog helps them forget their loneliness for a short time.

    Loneliness seems to be a common problem today. According to the Guardian, about 40 percent of American adults say they're lonely. And in the UK, about one in five people in the country are “always or often lonely”, The Telegraph reported.

    This might be why the UK government declared (宣布) the country's very first “Minister of Loneliness” (孤独大臣) in January. The minister's job is to find ways to help UK citizens feel less lonely. The minister's office will provide more money for activities that connect people together.

    This loneliness problem may be partly due to social media. When we see pictures of friends having fun or posting selfies (自拍) without us, we may compare their “perfect” lives with our own and feel inferior (较差的) and lonely.

    But we should remember that no one is destined (注定) to be lonely. As UK poet John Donne once wrote, “No man is an island, entire of itself; every man is a piece of the continent (陆地), a part of the main.”

    Tips to get rid of loneliness

    Sing your favorite songs.

    Connect with a friend.

    Do something creative, such as drawing a picture.

    Imagine some place you'd like to visit, like a fun gathering or a sporting event.