单项选择题
A．After the first snow falls in Colorado. B．Once they submit their applications. C．Before their sculptures are sketched. D．As soon as the judges have chosen the teams.
A．Wood. B．Snow. C．Ice. D．Rock.
A．Why Are Mobiles So Popular B．Mobiles--Useful or Useless C．Mobiles--A Danger to health D．Why Do We Design Mobile