in a week的用法和樣例：
例句
- How many days are there in a week? There are seven days in a week.
一星期有幾天？ 一星期有七天。 - You can't expect to learn a foreign language in a week.
不要指望一個星期就能學會一門外語。 - There are seven days in a week.
一周有七天。 - I sweated off ten pounds in a week by playing squash every day.
我每天打壁球，一個星期體重減輕了十磅。 - She washed her hair every night and measured how much it grew in a week.
她每晚洗頭髮，而且量量看一星期長多少。
