10/ "Did you go to school by bike yesterday?", Minh said to Hoa.
11/ "Why don't you take showers to save water, Mary?", Bill said
12/ "Don't write your name on this paper.", the examiner said to me.
13/ "Please read the instructions carefully.", the tourist guide said to the tourists.
14/ "Would you like to go to my birthday next Sunday, Daisy?", David said.
15/ "What about going to school by bike to save energy?", Mary said.
16/ "When should I start my English course?", Lan said to his teacher.
17/ "Should I tell my mother about this problem?", Ba said to Mai.
18/ "Who should I call for help, Bill?", Mary said.
19/ "Should we stay here?", the students said.