单项选择题
Speaker: Thank you all for your attention. Host: Professor Cohen, （）. Speaker: Sure.
A．we'd like to thank you anyway. B．I wish you a safe trip hack. C．would you like to take some questions D．could you expand on it
A．Do you need any help B．Are you here for holiday C．Are you new here D．What are you doing here
A．Not at all B．Yes, please C．I guess So D．I sure do