填空题 Before my kids go to school,I（ ）

判断题 Animals would start a fierce fight over food in ancient times.

判断题 The backyard of a dog owner may be full of holes dug by his dog.

判断题 Dogs started to bury their bones when they became pets.

判断题 Some dogs tend to store up more than one bone at the same time.

判断题 Dogs in the wild occasionally had enough food.

判断题 Dogs bury their favorite bones or chew toys by nature.

判断题 Dogs would bury their extra food for their babies.

判断题 Dogs often bury their bones far away from trees.