twice a week的同义词

问题描述:

twice a week的同义词
1.Her young sister takes a shower twice a week.(改为同义句)
Her young sister takes a shower_____ _____a week.
最好能解释清楚

two times 等于 twice 在三次之前,即一次或者两次,除了可用once twice之外,也可用one times two times表示,而三次以上的,就只能用times形式了