1 the engineer has built two railroads from 1990to2000
2 LU Yun is a writer and died in 1936)
3 my little brother started to learn Engliah when he was 7 years old
4 they walked on the Great Wall last week)
5 Billwill arrive here next Sunday)
6 all the students are listening to the teacher at the moment)
7 Roy was at his hometown five deays ago)