听力原文:W: Can we leave the lab now, teacher?M: No, you must tidy the lab before you leav
听力原文:W: Can we leave the lab now, teacher?
M: No, you must tidy the lab before you leave.
When can the student leave?
A.The student can't leave unless he has put everything back in the cupboard.
B.The student can leave after he turns off the electricity.
C.The student can leave after he has tidied the lab.