—I’d like to make an appointment with Doctor Smith．Would 9:00 tomorrow be all right?

—     ．Her schedule is full in the morning.

A．Yes, she’s free then

B．I’m afraid not

C．You must be joking

D．Wel1, it depends

三一班40人去玩“激流勇进”，每条船最多可坐6人，每条船租金58元．问至少需租几条船？共付租金多少元？