Chang these sentences into active :
1.Lan is helped by the teacher 2.I am surprised by the news 3.The letter will be posted by Lan 4.The cake has been eaten by the children 5.That letter was written by Linda 6.You will be amazed by this news 7.The letter is going to be answered by the secretary 8.Many people are employed by that company 9.The work will be done by Mr Manh 10.The window was washed by Mr Truong 11.This house was built in 1990 12.We have been invited to a party 13.That dictionary has been bought by my sister 14.Is spanish spoken in Peru? 15.Is English spoken by a large of people?