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【单选题】Human beings have used tools for a very long time. In some parts of the world you can still find tools that people used more than two million years ago. They made these tools by hitting one stone agai...
A.
disastrous.
B.
unpredictable.
C.
exciting.
D.
colourful.
【单选题】关于共价键修饰调节的叙述正确的是
A.
代谢物作用于酶的别位，引起酶构象的改变
B.
该酶在细胞内合成或初分泌时，没有酶活性
C.
该酶是在其他酶作用下，某些特殊基团进行可逆共价修饰
D.
调节过程无逐级放大作用
E.
共价修饰消耗ATP多，不是经济有效方式