Over time, these rivers cut deep into the new mountains.

VOA: special.2009.01.07

Now, for a long time in American scholarship and in American classrooms one of the deep mythologies about this whole story of the era of the American Civil War in the Old South is that the Old South's plantation economy was dying out.

在很长的一段时间中,美国学术界和美国课堂,对于这个时代内战前的南方历史,存有一个疑点,就是当时南方的种植园经济正在逐渐衰退

耶鲁公开课 - 美国内战与重建课程节选

The idea of a no-frills, environmentally-aware grave may,however, take time to catch on in Australia, where there is still a deep respect for tradition.

VOA: standard.2010.07.22

He tested the free-diving self-propelled submersible - one of only two in existence at the time - on increasingly deep dives off the California coast.

VOA: standard.2010.06.21

"This was a first and therefore you had to deal with his absurd and vile policies and the analysis of them had to take a long time and you had to get right down deep into him and how he thought,".

VOA: standard.2009.10.23