71. What is the main idea of this passage?
    A. Robots will soon be on sale              B. Robots are in great demand
    C. Robots are coming into our families.
    D. Robots help us a lot

                                 E
    There are good Santas（Father Christmas）and bad Santas. The good Santas all realize one thing: In the mind of a child，Santa Claus is perfect. That’s a lot of pressure. And so many people from around the world attend the Charles Howard School in Midland，Mich. The school offers a three-day，40-hour course for Santas hoping to achieve excellence. The graduates can get a diploma in the art of Santa.     
    There’s a real range to what Santas earn, from big reindeer（驯鹿）for large events to no pay for charities. One thing that makes them come here is a pure love for children，and very few jobs are respected by a shopping center full of children like Santas.
   “The very first time I did Santa，I was attracted，” said one of the students.“I would have done it without money. I mean，I just love it.” 
    A former Macy’s Santa named Chales Howard founded the Michigan School in 1937 with the belief that being St. Nick demands so much more than a belly and beard. “A lot of commercial institutes will