问题 选择题
 
Why not talk with your parents about your willingness to attend Peking University Summer Camp?   I tried __________to get them to listen to me.
                                                                                                                                                        [ ]
A. in time
B. in vain
C. in need
D. in case
答案

答案:B

不定项选择
单项选择题 A1型题