35．Which of these is a warning sign?

34．--Could you tell me _______ to go to Hainan by air?

--Just a minute, please．I have to check my computer．

A．how much does it cost                        B．how much did it cost

C．how much it cost                            D．how much it costs

33．I think teenagers in China should _______ to make their own decisions．

A．be allowed           B．allow               C．allowed            D．be stopped

32．Yuan Longping came up _______ an idea for a hybrid rice in the 1960s．

A．to                  B．with                       C．at                   D．in

31．--I am sorry to hear that．

-- _______．

A．I am sorry to hear that                       B．Please don't

C．Thank you for telling me                     D．God bless you

30．--What a hard life my parents live!

--So do my parents．When I grow up, I _______ to make them live more happily．

A．try                 B．tried               C．will try             D．have tried

29．I think you will _______ swimming．

A．have successful in                          B．have successful of

C．have success at                             D．be success in