题干

把下列物质分别加入装有水的锥形瓶里立即塞紧U形管的塞子,已知U形管内预先装有少量水(为使水容易观察,预先染成红色)。如图所示,结果U型管右边液面升高,则加入的物质可能是(  )
①NaOH固体 ②浓H2SO4 ③NH4NO3晶体 ④Na2O2 ⑤生石灰

A:①②④⑤

B:①②③

C:②③⑤

D:③④⑤

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A

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    Scientists today are making greater effort to study ocean currents (洋流) . Most do it using satellites and other high-tech equipment. However, ocean expert Curtis Ebbesmeyer does it in a special way -- by studying movements of random floating garbage. A scientist with many years' experience, he started this type of research in the early 1990s when he heard about hundreds of athletic shoes washing up on the shores of the northwest coast of the United States. There were so many shoes that people were setting up swap meets to try and match left and right shoes to sell or wear.

    Ebbesmeyer found out in his researches that the shoes — about 60,000 in total — fell into the ocean in a shipping accident. He phoned the shoe company and asked if they wanted the shoes back. As expected, the company told him that they didn't. Ebbesmeyer realized this could be a great experiment. If he learned when and where the shoes went into the water and tracked where they landed, he could learn a lot about the patterns of ocean currents.

    The Pacific Northwest is one of the world's best areas for beachcombing(海滩搜寻) because winds and currents join here, and as a result, there is a group of serious beachcombers in the area. Ebbesmeyer got to know a lot of them and asked for their help in collecting information about where the shoes landed. In a year he collected reliable information on 1, 600 shoes. With this data, he and a colleague were able to test and improve a computer program designed to model ocean currents, and publish the findings of their study.

    As the result of his work, Ebbesmeyer has become known as the scientist to call with questions about any unusual objects found floating in the ocean. He has even started an association of beachcombers and ocean experts, with 500 subscribers from West Africa to New Zealand. They have recorded all lost objects ranging from potatoes to golf gloves.