题目内容
根据句意和汉语提示在句子空白处填上合适的单词。
He does everything well because he is always ________(严肃的，认真的)about what he does．
答案：serious
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题目内容
根据句意和汉语提示在句子空白处填上合适的单词。
He does everything well because he is always ________(严肃的，认真的)about what he does．
_______________(保护)the environment.