有些事情，看上去真的是完全多余的。
你这样为她着急完全多余，她好好地在家里哩。
You don't need to be worrying about her. She is safe at home.
海洋不会变得酸性那么大以至于贝壳完全溶解掉，但是多余的酸意味着要产生这些贝壳将是很困难的，这会严重破坏海洋生态平 衡。
The sea would not become so acidic that shells would actually dissolve, but the extra acidity would mean making them was harder work, which might upset the oceanic ecosystem quite badly.
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