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问题 选择题

下列物质属于合金的是

A．汞

B．生铁

C．塑料

D．氧化铁

答案

答案：B

题目分析：汞是纯金属；塑料不是金属材料；氧化铁是氧化物；生铁是铁和碳等的合金。选B。

点评：合金是金属和金属或者金属和非金属融合而成的具有金属特性的物质。

完形填空

When very small dinosaur bones were found in a Germany mine, people thought they were from baby dinosaurs. ___小题1:_ Martin Sander's work shows that they were probably fully __小题2:__ (grow) and belong to the smallest giant dinosaur species ever found.

Growth marks on dinosaur bones are similar __小题3:__ growth rings on trees. The rings are far apart while the animal is young and growing quickly. __小题4:__ get closer as growth slows. "It is _小题5:__ (exact) these tight ring marks that we found in the fossil bones," says Sander. So the fossils must have been from adult animals.

__小题6:__ was this German dinosaur so much smaller than other giant dinosaurs, which grew up to 45 metres long and weighed as much as a thousand humans?

150 million years ago, most of Germany was underwater. Scientists think that __小题7:__ water levels rose, there was less and less land and food available. The dinosaur _小题8:__ (need) less space and food.

Since 1998, scientists have dug up more than 1,000 dinosaur fossils in the mine. It is one of the few places in the world __小题9:_ the bones and footprints of dinosaurs have been found together.
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选择题

要想了解我国古代江河流经地区的山川、城镇、物产、矿藏、风光等情况，可以阅读 [ ]

A．《千金方》

B．《论衡》

C．《三国志》  

D．《水经注》  
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