More thunderstorms （）in summer than any other time of the year.

A．competed in a 200-meter race
B．wrestled with each other
C．read the accounts of he games
D．received the treatment of free dinners

A．Why Are Mobiles So Popular
B．Mobiles—Useful or Useless
C．Mobiles—A Danger to Health
D．Why Do We Design Mobiles