“深入的”用英语怎么说？

这是个新课题,需要深入的研究.This is a new subject and needs to be explored in depth.让我们做一次深入的研究.Let's make an exhaustive study.想要对这个问题有更加深入的了解，读读它会受益匪浅。It makes invaluable reading for anyone who wants to acquire a greater depth ...