He thought that this was evidence that the bottom of the ocean had been lifted up by powerful geological forces over long periods of time.

VOA: special.2009.02.25

Taq stands for thermos aquaticus, it's a marine micro-organism that lives near these hydrothermal events in the bottom of the sea and they live under very high temperatures and pressures all the time.

aq是"水生栖热菌"的简称,那是一种生活在靠近深海热液活动区的,海底微生物,它们长期生活在高温高压的环境中

耶鲁公开课 - 生物医学工程探索课程节选

When a student's grades hit bottom it is time to hit the books.

VOA: special.2009.09.20

"The bottom line: it is now time for our fiscal authorities to do what fiscal authorities are paid to do, why they were elected to Congress: bring about some balance.

VOA: standard.2010.04.21