He seems confident but deep down he's quite insecure.

他好像很有信心，实际上却没什么把握。

《牛津词典》

We know every note in every composition, but if you ask what is music, and where does the musical part of music come from, you’re in a quite deep philosophical conversation.

我们知道每一个作品中的每一条信息。 但是如果你问音乐是什么，音乐中的那一部分来自哪里，你将陷入一种深深的哲学性的对哈中。

youdao

The ideas underlying Pythagoras's theorem and its generalization are quite deep, but no mathematicians now would find them difficult.

蕴涵在毕得哥拉斯的定理和及其概括中的观念非常深，但现在的数学家没人会觉得他们很难。

youdao

Over the years, I have known quite a few traders and several with quite deep pockets, but very few would ride a 17% gain to a loss, By early June 2012, ( UTX) was down 5% for the year.

FORBES: 5 Rules for Success in 2013

But United is in deep trouble: it filed for bankruptcy protection last year and it now seems quite likely to shut down altogether.

ECONOMIST: Economics focus

There has been much heated debate this week about how much more oil there is to come - probably a lot, but not necessarily offering up quite such generous tax revenue once the industry has been incentivised to drill and develop in deep water and hard-to-reach reserves.

BBC: Scottish independence: Fjords flowing with funds