题目

—      should teenagers spend at least 30 minutes taking exercise?     —Five times a week，according to some reports．     A．How much    B．How soon    C．How long    D．How often 答案：DA：It isn't going to rain, is it? B：________. [　　] A．Yes, I don't hope so B．Yes, it isn't C．No, I hope not D．No, it doesn't