---How can I keep healthy?---I think you ought to_________.A.do more exerciseB. doing more exerciseC. exercising more
---Natural disasters are dangerous! ---Yes,________ earthquake that happened in Philippines killed __________ number of people.
The teacher asked the students _________________.
A low-carbon(低碳)lifestyle has an effectour daily life. More and more attention has been paid toenergies these days.
The teachers ________________ the office for a few minutes when we arrived.
——Would you mind my opening the window? ——__________.