昨天星期几 ---ItisSunday(today)
---What day is it today?
---It is Sunday (today).
---What day was it yesterday?
---It was Saturday (yesterday).
---What day is it tomorrow?
---It is Monday (tomorrow).
?
---What day is it today?
---It is Sunday (today).
---What day was it yesterday?
---It was Saturday (yesterday).
---What day is it tomorrow?
---It is Monday (tomorrow).
?