In nineteen eighty-three, he began to study more than twenty-two thousand healthy male doctors over forty years of age.

VOA: special.2009.10.20

One over two squared minus one over n squared 3 4 5 where n takes values three, four, five, six.

除以，2，的平方再减去1除以n的平方,将n赋值为。

麻省理工公开课 - 固态化学导论课程节选

The debris now circles the Earth in orbits from two hundred kilometers to over three thousand eight hundred kilometers.

VOA: special.2009.04.01

Each program brings together different subjects and extends in length over two or three quarters.

VOA: special.2009.03.05

More recent research suggested that those gains are the same whether you exercise for short periods over five days or longer sessions over two or three days.

VOA: special.2010.06.08

He says that in the Antarctic Peninsula, scientists estimate that climate change has caused temperatures to increase by two or three degrees Celsius over the past fifty years.

VOA: special.2009.06.03

Kashmir is split between the two countries, which have fought two of their three wars over the Himalayan region.

VOA: standard.2009.10.28

Over the next two days, President Obama will take part in the summit's three plenary sessions, along with multilateral and bilateral meetings with fellow-leaders.

VOA: standard.2009.04.17

In the course of one concert, we play for a larger live crowd than all but I think two or three orchestras in the entire country play for, over the entire year.

VOA: standard.2010.07.28