【简答题】通常情况下,平均每人每天需要消耗氧气约0.9kg,呼出二氧化碳约1.0kg.在1.0kg的二氧化碳中含氧元素质量约0.73kg.假设人体吸入的氧气只用于糖类[以淀粉为例,化学式为(C 5 H 10 O 5 ) n ]和油脂[以油酸甘油酯为例,化学式为C 57 H 104 O 6 ]的完全氧化.根据糖类和油脂的分子构成,解释消耗氧气的质量大于呼出二氧化碳中氧元素质量的原因.
【单选题】The typical type of sentences in news reports, science and technology, narration, expository writing, etc. is sentence as its function is to provide information which serves the purpose of the texts.