inquire thoroughly into

基本解释

They determined to inquire thoroughly into the matter.
他们决定彻底调查这件事。
《新英汉大辞典》
It matters not what you inquire into, but when you inquire into a thing, you must never give it up until you have thoroughly understand it.
探究什么并不重要，然而，一旦你探究某一事物的时候，就必须彻底的理解它。
blogmaverick.blog.163.com
It matters not what you inquire into, but when you once inquire into a thing, you must never give it up until you have thoroughly understood it.
重要的不是你试着想想，但当你曾经设法想出一件事，你必须不放弃它直到你已经得到你想要的东西。