题干

某课外活动小组在探究物体的“浮沉条件”时,将一个质量为100 g的物体放入装满水的深桶中,溢出90g水,物体受到的浮力是____N(取g=10 N/kg);这个物体在水中将会____(选填“上浮”“下沉”或“悬浮”)。放入物体后水对桶底的压强____(选填“大于”“小于”“等于”)放入物体前水对桶底的压强。
上一题 下一题 0.0难度 选择题 更新时间:2019-06-18 09:41:39

答案(点此获取答案解析)

0.9,下沉,等于

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完形填空

    Walking down a path through some woods in Georgia, I saw a water puddle (水坑) ahead on the path. I walk around to the side of the path that wasn't covered by water and1.As I reached the puddle, I was suddenly attacked! Yet I did nothing for it was so2I stepped back and my attacker stopped attacking me3attacking more, he flied in the air with its graceful4in front of me. Had I been hurt, I wouldn't have found it amusing but I was unhurt, it was5 and I was laughing. After all, I was being attacked by a butterfly!

    I took a step forward, and my attacker rushed me again. He pushed and 6.Me in the chest with his head and body over and over again with all his might. It's just not everyday that 7is attacked by a butterfly, so I stopped to find out the 8My attacker moved back as well to9 on the ground. That's when I discovered why my10was charging me only moments earlier. He had a mate beside the puddle11he landed and she was dying.

    Sitting close beside her, he opened and closed his wings as if to fan her. I could only12the love and courage of that butterfly in his concern for his mate, even though she was 13dying and I was so large. He did so just to give her those extra few 14moments of life. Now I knew why and what he was 15I couldn't do anything other than reward him by changing my 16 to the more difficult side of the puddle. He had truly 17 those moments to be with her, undisturbed. I cleaned the mud from my boots and left.

    Since then, I've always tried to remember the 18of that butterfly whenever I see huge 19 facing me. I use that butterfly's courage as an inspiration to 20myself that good things are worth striving for.