第1个回答 2015-02-28
it's very important for us to drink a cup of milk every day
第2个回答 2015-02-28
It's very important for us to drink a glass of milk everyday.
第3个回答 2015-02-28
Drinking a cup of milk every day is very important for us
追答另一个回答也是正确的
第4个回答 2015-02-28
it's important for us to drink a glass of milk every day.