[视听材料] 老托福阅读 托福, 阅读

shimianmaifu

老托福阅读
All mammals feed their young. Beluga whale mothers, for example, nurse their calves for some twenty months, until they are about to give birth again and their young are able to find their own food. The behavior of feeding of the young is built into the reproductive system.【资料下载】老托福阅读