PartA ReadingAloud(模仿朗读)
Inthispart,youarerequiredtowatchavideoclipandreadafterthespeakerinthevideo.
The proportion of gases is important not just for breathing but also in order to filter out the sun’s rays and keep the planet’s temperature constant.Scientists discovered it over the last few decades,the composition of the atmosphere in every part of the globe has started to change.The reason for this is the carbon dioxide is more abundant each year,increased levels of carbon dioxide change the proportion of gases in atmosphere,and this affects how the climate on earth is regulated.Why did these strange changes occur?The reason is easy to understand.
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