v.(使)成三倍( treble的现在分词 );
例句:
As the voltage was abruptly trebled the valves burnt.
由于高压突然增加了两倍,电子管全烧坏了.
He's trebled his earnings in two years.
他两年间收入已增加两倍.
It's value has trebled.
它的价值已增长到原来的三倍.