First get students to form groups of four.

　　首先讓學(xué)生分成四人一組。

　　Students come here from the four corners of the world.

　　學(xué)生從世界各地來到這里。

　　We are in competition with four other companies for the contract.

　　我們在與其他四家公司競爭這項合同。

　　Four points stand out as being more important than the rest.

　　有四點比其余各點更為重要。

　　Don't let this go further than these four walls.

　　走出屋外這事就不要再談了。