当外界温度等于或高于体表温度时，机体散热的主要方式是

A．传导

B．对流

C．辐射

D．辐射和对流

E．蒸发

–We ‘ll be back for our school’s _____anniversary (周年) ceremony .

-I see. That means you’ll have a get-together with your classmates in ____years .

A．twelve; seven

B．twelfth; seven

C．twelve seventh

D．twelfth; seventh