r used in negative statement to describe a situation that has existed up to this point or up to the present time
adv. 迄今, 至今
1. The project has hitherto been successful in achieving its goals.
这个项目迄今为止在实现其目标方面是成功的。
2. Hitherto, we have not encountered any major problems.
迄今为止，我们没有遇到任何重大问题。
3. Hitherto unknown species have been discovered in the rainforest.
在雨林中发现了迄今未知的物种。