Open the （）before starting an air compressor.
Lesson plans are useful only before the lesson.（）
Before entering the chain locker，you should（）.
I will wait for Utopia（）before getting underway.
Children need to be（）before entering school.
Before I got to the cinema, the film（）
Before starting an air compressor, It should be （）.
Dirty oil must be （） before being used again.
Before reassembling any machinery, you should （）.
Before the sludge in a purifier is ejected,（）
Many a student ___that mistake before.
Please _____ before entering.
She …………….. before too long.
纠错 Having finished his term paper before the deadline , it was delivered to the professor before the class.
纠错Having finished his term paper before the deadline, it was delivered to theprofessor before the class.
He poured out his _ before me.
Why is Lucy eating less than before?
All visitors tothe lab(expect) ______ before to take off their shoes before they enter.
Before long，the noise dropped eompletely．
days before the holiday season的意思 days before the holiday thank you~
What occurred before Baju went to sleep？
He felt___before the final exam.
Think it over before you speak.（翻译）
下面哪个关于伪元素选择器before的说法是错误的？
