C．calmly

　　D．deeply

　　20．A.something

　　B．anything

　　C．everything

　　D．nothing

　　三、阅读理解

　　Rising levels of carbon dioxide in the atmosphere are a major cause of climate change，and now a new study has confirmed that atmospheric CO2 is also affecting the ocean chemistry and potentially harming sea life.

　　Montana State University scientist Robert Dore has been researching the water in the Pacific Ocean for almost two decades.

　　“We've been going to the same spot in the Pacific Ocean，and we try and characterize long­term change in the open ocean environment.And one of the key things that we measure is CO2 levels.And we've been able to record this increasing quantity of atmospheric CO2 into the ocean.”

　　Scientists expected that as atmospheric CO2 increased，more and more of the carbon dioxide would be absorbed into the ocean，affecting the chemical balance of the sea water，with a potentially harmful impact on shellfish and coral in particular.

　　“As carbon dioxide dissolves(溶解)in the water or seawater in this case，it forms a weak acid，carbonic acid，”Dore explains.“And therefore，as the concentration of CO2 in the atmosphere goes up and that exchanges with the surface seawater，it drives the pH down，and makes it more acidic.”

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