阅读下面一则对话，在空白处填入适当的句子，使补全后的对话意思完整，结构合理，上下连贯。
每个空白处只能填写一个句子。
A: Hi! You look unhappy. (1) ____________________?
B: I got very bad news from the News Report. It happened in Jiangsu Province.
A: What was it?
B: A crazy man entered a kindergarten and wounded (杀伤) 31 persons, including kids and teachers.
A: (2)____________________. Something must be done to keep schools safer.
B: Right. (3) ____________________ when I grow up. Police can protect them from being hurt.
A: I think that's a good choice. (4) ____________________ if you want to be a policeman?
B: I am going to study harder and exercise every day to be stronger.
A: Oh, cool enough! I wish your dream come true.
B: Thank you.
1．What happened to you / What's the matter / What's wrong / Anything wrong / What's your trouble
/ What's up
2．That's terrible / That's too bad / Bad enough / (I am) sorry to hear that / How terrible
3．I want / wish / plan / hope / would like to be / become a policeman / I'm going to / will be a policeman
4．What are you going to do / How are you going to do that / What's your plan
(答案不唯一)