请以"Amazing things"为题写一篇70左右的文章

Pigs are much more intelligent than what many people give them credit for!
Professor Stanley Curtis and Dr. Sarah Boysen of Penn State University in a study found that pigs are much smarter than dogs. Pigs are capable of abstract representation and are able to hold an icon in mind and remember it at a later date. Pigs did better at video games than some primates. Pigs communicate constantly with one another and more tha 20 of their oinks have been identified for different situations, from wooing their mates to saying "I'm hungry". They have temperature preferences and can learn through trial and error how to turn on the heat in a cold barn and turn it off again when it is too warm. Pigs have even saved the lives of their owner by dragging her free from a muddy bog.