guoxiaotian

with Ruby 1.9 you don't need the '=>' for hash values:

    class Person < ActiveRecord::Base
      attr_accessible :first_name, :last_name
      validates :first_name, length: { maximum: 30 }
      validates :last_name, length: { maximum: 30 }
    end

"most of the flat-screen TVs sold in the United States, from companies like Samsung and Sony, are made there, along with everything from medical devices to aerospace parts."

Not sure about medical devices or aerospace parts, but one of the reasons those float-screen TVs are "made" there is the tax advantage. They were mostly made in Asia and the final assembly was done in Mexico.

Still, you have to start from somewhere.