sentences: animals require food to survive & a bear is a kind of animal -> germs are a mean of plant that require poison to survive bears are a kind of animal that require food to survive  germs are a mean of plant that require poison to survive & an animal will look for food in places that usually / sometimes contain food & a garbage can sometimes contains food -> bears will learn to look in a garbage can for food to survive bears will learn to look in a garbage can for food to survive  bears will learn to look in a garbage can for food to survive & airport in a orbit sometimes requires closing that pulling -> bears will learn to open the garbage can to look for food