请认真阅读短文，从短文后各题所给的A、B、C、D四个选项中，选出最佳选项。

Can the time go slower?

— by Joanna Pitt

Can the time go slower?

I'm still thinking of

the answers.

Can the time go slower?

My head is not

yet clear.

Can the time go slower?

For me the rules of math are

too hard to remember.

Can the time go slower?

My grade is what my father

really cares about.

So can the time go slower?

My dear teacher,

I don't want to run behind others.

Oh no!

There are still lots of questions

to be answered!

蛋白质是由多种氨基酸构成的极为复杂的化合物，丙氨酸（C₃H₇O₂N）是其中的一种．以下对丙氨酸的认识错误的是（  ）