是副词词性。
adv. 两次；两倍She'；s backpedalled twice already.
她已经两次改变主意了。
I go swimming twice a week.
我每星期游泳两次。
The villa is cleaned twice a week.
这栋别墅一周打扫两次。
Cats sleep twice as much as people.
猫睡觉的时间比人长一倍。
I visited once or twice.
我参观过一两次。
twice是什么词性
是副词，与动词一起使用，表示做某事的频次。
