First get students to form groups of four.
首先让学生分成四人一组。
Students come here from the four corners of the world.
学生从世界各地来到这里。
We are in competition with four other companies for the contract.
我们在与其他四家公司竞争这项合同。
Four points stand out as being more important than the rest.
有四点比其余各点更为重要。
Don't let this go further than these four walls.
走出屋外这事就不要再谈了。