题干

某实验室用两种方式进行酵母菌发酵葡萄糖生产酒精。甲发酵罐中保留一定量的氧气,乙发酵罐中没有氧气,其余条件相同且适宜。实验过程中每小时测定一次两发酵罐中氧气和酒精的物质的量,记录数据并绘成下面的坐标图。据此下列说法中正确的是(  )

A:在实验结束时甲、乙两发酵罐中产生的二氧化碳量之比为6:5

B:甲发酵罐实验结果表明在有氧气存在时酵母菌无法进行无氧呼吸

C:甲、乙两发酵罐分别在第5小时和第3小时无氧呼吸速率最快

D:该实验证明向葡萄糖溶液中通入大量的氧气可以提高酒精的产量

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答案(点此获取答案解析)

C

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    Some 30,000 years ago, artists who lived in caves in Europe painted pictures of the animals around them: panthers, hyenas, rhinos, cave lions, mammoths and other creatures which have been extinct for a long time. The paintings were highly realistic. Some even showed movement.

    The artwork, more than a thousand drawings, is considered the oldest group of human cave drawings which have ever been discovered. They were preserved because the cave was sealed---closed off--for more or less 23,000 years.

    Fast forward to December 18, 1994, a group of French cave scientists were exploring caves in southern France. Jean Marie Chauvet, who led the group then, describes the process of discovering the cave paintings. “At that time I was in the front, Eliette just walked behind me, Christian behind. Eliette said she saw two marks with red ochre and she said, ‘They came here.' And at this very moment everything began. The drawings and everything linked to the parietal art(壁画). That is where it is tarted.”

    Cave art expert Jean Clotttes reviewed the paintings. “I was amazed at the number of paintings there were and paintings of their quality and particularly in front of the panel of the horses.”

    Scientific analysis confirmed the prehistoric date of the artwork. Studies showed the drawings were created tens of thousands of years ago, before human history was written. The United Nations' cultural agency UNESCO lists the cave as a World Heritage Site. They say that the drawings form a remarkable expression of early human artistic creation of grand excellence and variety.

    The Chauvet Cave has been named after the explorer who first entered it. However, its environment and drawings are too fragile to be visited by human beings. So the cave is closed, and only people there for scientific purposes can go inside and see the artwork.

    However, French authorities asked experts to create an exact copy of the cave, called Pont d'Arc Cavern. The copy, which we also called replica, cost more than 59 million dollars to build. It opened at the end of April in France.

    Pascal Terrasse is the president of the cavern. He says everyone will be able to experience the thrill of looking at drawings made by the first humans in Europe. He says the place is magic because it is done so well. Authorities say they think as many as 400,000 people will be allowed to visit Pont d'Arc Cavern every year.