深入的英文：
penetrate deeply
thorough

参考例句：

Conduct an intensive and comprehensive investigation and study
作深入全面的调研

He was deep in thought.
他深入思考。

Deep down, I look on reading as saint thing.
深入地说就是我把读书视做神圣的东西。

The senescence of fruit, i.e. the deteriorative events which occur after ripening, has not been intensively studied
果实的衰老，也就是成熟以后所产生的败坏过程，尚未被深入地研究。

She clutched the mask and breathed short and deep, pantingly, making the respirator click
她抓住面罩，呼呼地吸气，又短促又深入，弄得呼吸器答答响。

Mao was an accomplished scholar of Classical Chinese, an omnivorous reader, a deep student of philosophy and history
毛泽东还是一个精通中国旧学的有成就的学者，他博览群书，对哲学和历史有深入的研究。

To penetrate deep into wilderness or uncivilized regions
深入不毛

A deep thrust into the opponent's territory
深入对手范围内的猛攻.

From the shallower to the deeper;proceed from the simple to the more complex;from the superficial to the deep
由深入浅

Farthest within;innermost.
最深入的;最内部的

penetrate是什么意思：
v. 渗入，刺入，穿透；进入，跻身，潜入，渗透；洞悉

tip penetration
磁头尖插入度

The nail will not penetrate.
这枚钉子钉不进去。

These are the result of the penetration of the larvae into the crypts
这些是幼虫钻入滤泡的结果。

deeply是什么意思：
adv. 在深处；浓浓地；深刻地，强烈地

To be deeply ingrained in the mind.
深深印于脑海中。

The inscription is deeply cut on the stone.
碑文已深深地刻在石头上。

Inhale deeply, please.
请作深呼吸。

thorough是什么意思：
adj. 彻底的；十足的；周密的

thorough swindler
彻头彻尾的骗子

He is a thorough scoundrel.
他是一个十足的无赖。

That has been a thorough waste of time.
这是十足的浪费时间。