adj.三倍的；三重的
adv.三倍地；三重地
The graphs show a threefold increase in the number of. 该图表表明数目增长了三倍。
The result: wood theft went up threefold. 结果是：树木偷伐量增长了3倍。
In just over a year's time, membership has increased threefold. 在短短一年间，成员人数已增加三倍。
