It is in this laboratory ______ is run by Mr. Wu ______ the experiments are done.
No one helped me . I did it all myself .
Don't try to get off the bus ____ it has stopped.
To understand the grammar of the sentence,you must break it______ into parts.
He will tell you about it ____ you get there.
The classroom is big enough , but we’ll have to move if we have more students.