大学英语：They concern the common things of life

　　3.They concern the common things of life， and are the stock in trade of who speak the language concern 在句中的意思是“涉及，有关于”，如：

　　1)Don't interfere in things that don't concern you (别干预跟你无关的事)。

　　2)The energy problem concerns us all (能源问题关系到我们每个人)

　　stock的意思很多，如“存货”，“股票”，“公债券”，“牲畜”等。

　　1)They hold a rich stock of information (他们掌握着丰富的材料)

　　2)You cannot buy it because it's out of stock (你买不成了，货品已经脱销)

　　3)He used to have a stock farm (他曾经拥有一个畜牧场)

　　4)The fridge was carefully stocked up with food.(冰箱里周到地放满了食品)

　　stock in trade 也可以写成stock in trade，意思是“例行工作”，“常规”，如：

　　1)Complaints were a stock in trade of an airport manager's job (机场经理的工作就是常常面对投诉)

　　2)He was the master of black humor， it was his stock in trade (他是黑色幽默大师，黑色幽默是他的专长)