下面哪种物质能与硫酸铜的碱性溶液发生显色反应,生成紫红色化合物。()
A. 氨基酸
B. 二肽
C. 寡肽
D. 多肽
E. 蛋白质
下面关于酶的叙述正确的是()。
A. 酶是由活细胞产生的
B. 酶只能催化特异的底物
C. 酶具有高效催化作用
D. 酶的化学本质是蛋白质
E. 一切能够使蛋白质变性失活的因素都可以使酶变性失活
Over the next two decades ________ wrote a succession of widely acclaimed plays which may be categorized roughly into three groups: histories, comedies, and tragedies or tragicomedies.
A. his
B. it
C. he
D. him
________ can be said that the adoption of shifting perspective is one of the characteristics of Chinese painting.
A. That
B. What
C. It
D. Which