题目

下列各项所涉及的变化中，蛋白质肽键数目减少的是（ ） A . 消化道内蛋白质的消化 B . 氨基酸脱水缩合 C . 蛋清中加入食盐导致蛋白质析出 D . 高温导致蛋白质变性 答案：AAfter he was promoted to the present position, he is not so hardworking as he ______.   A. was used to    B. used to be     C. was used to being   D. used to