The cough is just dry cough, but very persistent, nothing seems to work.

这个咳嗽是一种干咳，但是就是一直治不好，什么药都没什么疗效。

youdao

Non-persistent messages are processed in memory and are very fast, but may be lost in the event of a system failure.

非持久化的消息是在内存中进行处理的，速度很快，但可能会因系统故障而丢失消息。

youdao

At sales I was not very good. I was persistent, but I didn't have the smoothness of a good salesman.

销售业务并不好做，我虽然一直在坚持，但明显我没有一个优秀的推销员所需要的那种耐心和诚恳。

youdao

But also a very persistent one, despite there being clear evidence that it is not.

FORBES: Management myths