—Can you help me with the bike?

—Sorry, I’m a little busy now. Read the instruction. It______, “Do it yourself”.

A．speaks

B．talks

C．tells

D．says

三羧酸循环中草酰乙酸的补充主要来自于

A．苹果酸脱氢生成

B．丙酮酸羧化生成

C．乙酰CoA缩合后产生

D．柠檬酸分解产生