Listen! David is talking happily with his mother in the next room.　— It ______ be his mother. She has gone to Yunnan to be a volunteer doctor.

The teachers often tell their pupils _____ across the road when the traffic light is red.

Is there ________________ about the event of the missing Malaysia Airlines plane(马来西亚飞机失踪事件)in today’s newspaper?

Our teacher is good ______singing English songs.[ ]

My hometown is a wonderful place. I hope you _________ soon.