1.Linda there's somebody knocking at the door.2.You are supposed to ask the teacher if you want to leave the classroom during class.3.I am not sure whether he will come back tomorrow or not.4.I bought a new mobile phone that is very similars to the one I had before.5.In the last century more than 60 percent of the students were from the countryside.6.The sports shoes must be Linda's.No,they can't be. They are too small for her.7.Frank will see the new film if he's free this weekend.8.EnShi is becoming a tourist city .Thousands of people come here during the holidays.9.Believe in him. He has the ability to work it out.10.His back was injured in the earthquake.