"我早就知道啦!”的意思.
用在当别人和你说一件你很清楚的事情的时候,你就可以这么说拉!
E.G.：
Flevy:How often do you brush your teeth?
Jacky:After every meal.I want to keep them healthy.
Flevy:Me too.But do you floss?My dentist says that's very important,too!
Jacky:You're telling me!I have been flossing my whole life!