________ students are in the classroom.

There ____ lots of bad information that is not suitable for teenagers on the Internet.

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.

Why are you so late?—I was in half the way when it______to me that I had left my notebook home，so I had to fetch it.

Father some bread for breakfast this morning.