Many schools use small classes as their trump card in marketing campaigns.

很多学校在做传活动时都把小班授课当成他们的。

The competition and prize of a free car is a sprat to catch a mackerel. The publicity will mean good business for months to come.

办竞赛并开出免费汽车的獎品不过是小钓饵。这一传活动会使随后的几个月生意兴隆。