单项选择题
A．it senses a coming danger B．it is forced to swim on a hot day C．it is short of its favorite food D．it wants to keep itself to itself
A．The sloth has only three toes B．The sloth lives in the damp jungle of South America C．The sloth usually tries to find a new spot for food at night D．The sloth will never fight with other animals
A．to help children to gain a better understanding of animal life B．to prove that the saying "a rolling stone gathers no moss" is wrong C．to introduce a particular animal to the common reader D．to discuss with professionals the laziness of animals