Without the development of the Internet, Taobao and Tmall______$ 5.7 billion in sales on 11 November, 2013.

It’s hard to say what kind of person he is. Sometimes he is very nice; at other times he _______ be very cold.

---What did you say to Julia? I saw her crying in the dormitory alone. --- It ______ my fault. We talked happily when I was with her in the classroom.

The professor ________at 8 o’clock，but he has not shown up yet，which worries all of us.

 It was the order that all the soldiers ________to the front.