题干

今年小明家种植柑橘获得了丰收.小明想:柑橘的密度是多少呢?于是,他将柑橘带到学校实验室,用天平、溢水杯来测量柑橘的密度.他用天平测出一个柑橘的质量是100g,测得装满水的溢水杯的总质量是360g;然后借助牙签使这个柑橘浸没在溢水杯中,当溢水杯停止排水后再取出柑橘,再测得溢水杯的总质量是240g.(g=10N/kg)

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同类题2

阅读下列短文,从下面每小题的 A、B、C、D 四个选项中选出最佳选项。

B

    Last summer, Mac Hollan, a primary school teacher, was cycling to Alaska with two friends. On the way, his friends had to stop for a bicycle repair, but they encouraged Mac to ride on, and they would catch up with him soon.

    Mac began to cycle alone. A few minutes later, Mac heard quick and loud breathing behind him. "Man, that's a big dog!" he thought. But when he looked to the side, he saw immediately that it wasn't a dog at all, but a wolf, quickly catching up with him.

    Mac's heart jumped. He searched and took out his can of bear spray(防熊喷雾). With one hand on the bars, he fired the spray at the wolf. A bright red cloud enveloped the animal. To Mac's relief(宽慰), it fell back, shaking its head. A minute later, however, it was again by his side. It even attacked the back of Mac's bike, tearing open his tent bag. He fired at the wolf a second time, and again, it fell back, only to quickly restart the chase(追赶).

    Mac was riding hard now. He waved and shouted at passing cars without slowing down.

    At that moment, Paul and Becky were driving their car on their way to Alaska. They found a dog-like animal running alongside a man on a bike. As they got closer, they realized that the "dog" was a wolf. Mac heard a large car behind him. He kept waving and shouting as the wolf was catching up closer. And the car did stop in front of him at the right time.