直到失去健康你才会意识到它的重要性。
.
当你说英语的时候不要害怕犯错误。
making mistakes when you speak English.
他过去常常吸烟,但是现在他已经戒掉了。
He smoke,but he has already given it up.
在你离开教室之前,确保窗户都关好。
the windows are closed before you leave the classroom.
我记得在聚会上连续唱了三首歌。
I remember singing three songs at the party.
他已经入党20年了。
He the Party for 20 years.