but和and能同时在一个句子中吗?

Question

比如下面这个句子:
But it had been very difficult to store Chinese information in computers before the invention,and it had been even harder to process it.

Answer 1

可以，但是建议这样说比较简洁：
But it had been very difficult to store Chinese data in computers before the invention, and even harder to process it.

Answer 2

可以

Answer 3

可以

Answer 4

我觉得可以

Answer 5

换成 yet