关于正电子药物的描述，下列正确的是（） A.11 C、13N、15O和18F等短半衰期

情景对话,从方框中选择最佳答案补全对话,有两项是多余的.(5分)

A、Really? B、Why do you like it so much? C、Will you have a holiday? D、But which country do you like best? E、Which country do you want to go? F、Have a good time. G、Do you want to go abroad for your holiday?

A: We’ll have a holiday next week.
B:    1   . Where are you going to spend your holiday?
A: I want to go abroad for my holiday.
B:    2  
A: Many countries, such as Italy, Japan, Britain, Australia and so on.
B: That sounds good!    3  .
A: My favourite country is Australia.
B:     4    .
A: Because I really want to visit the Sydney Opera House and the Habour Bridge, and the people there are very polite.
B: I agree with you.     5   .