一块浮动隔板将清洁的水面与含单分子层的水表面隔开。
A floating barrier separates a clean water surface from a water surface containing the monolayer.
有些鱼类能吃掉杂草从而保持湖塘、水道的清洁。中国草鱼即是一例，它能吃掉大量狐尾草之类的长在水面下的杂草。
Some kinds of fish will keep lakes and water-ways clear by eating water weeds. the Chinese grass carp is one. it eats large amounts of water milfoil and other weeds that grow under the water surface.
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