W: Can we leave the lab now, teacherM. 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.
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.
举一反三
- He ________(turn)off the light. We can leave now.
- You ______ a tip if you're not satisfied with the service. A: mustn't leave B: must leave C: can leave D: don't have to leave
- You can turn on the air conditioner before you go home or turn off the light after you leave through the smart phone.
- He ( ) the school. His cellphone is still on the desk. A: mustn't have left B: can't leave C: needn't leave D: can't have left
- not until, get everything ready,he,for the experiment, leave, the lab,Xiao Wang (It was …that …)