补全对话。从方框中选出适当的句子补全对话。
A: May I help you?
B: Yes, please. I’d like to borrow a book.
A: ____ 
B: Jane Eyre.
A: Wait a minute.____ Sorry, it has been borrowed.
B: ____ . What about Romeo and Juliet?
A: Yes.____ .
B: Thank you.____ 
A: Two weeks. You must finish reading it and return it on time.
B: I see. Thank you. Goodbye.
A: Goodbye.

“一个幽灵，共产主义的幽灵在欧洲徘徊。”马克思、恩格斯在19世纪中期写下了这句名言，创立了一种新的社会主义理论。这种新的社会主义理论诞生的标志是（   ）