Please reply in writing by Saturday.
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.