书写体系当时还没有创造出来。用英语怎么说？

书写体系当时还没有创造出来。

Writing had not been invented as yet.

writing

n. 文字，写作，文章，笔迹；v. 写（ write的现在分词），写信；

例句
...teaching the basics of reading, writing and arithmetic.
教授阅读、写作和算术的基础知识

had

v. 有（ have的过去式和过去分词 ），（亲属关系中）接受，拿，买到；

例句
He claimed that his parents had abandoned him...
他声称父母遗弃了他。

not

adv. 不，[用以表示否定、否认、拒绝、禁止等]不是，几乎不，未必，没有[用于否定后面的词或短语]；

例句
It became very clear that the incident was not just an aberration, it was not just a single incident.
事实已经很清楚，这件事不是偶发的，它并不是一起孤立的事件。

been

v. 用来表示某人或某物即主语本身，用来表示某人或某物属于某一群体或有某种性质（ be的过去分词 ），在，存在，不受干扰，去过了，be的过去分词；

例句
Have you been able to have any kind of contact?...
你联系上了吗？

invented

n. 虚拟；v. 发明，创造( invent的过去式和过去分词 )，编造；

例句
I launched into the parable, embellishing the story with invented dialogue and extra details...
我开始讲那则寓言，并编造了些对话，加了些细节对其进行润色。

as

adv. 同样地，一样地，例如；prep. 作为，以…的身份，如

例句
As far as I can recall, Patti was a Smith.
我记得帕蒂是姓史密斯的。

yet

adv. 但是，还，已经，又，再；conj. 然而，但是；

例句
She had not yet become accustomed to the fact that she was a rich woman.
她还不太适应已经是一个富婆的事实。