关键期假说关键期假设(英文:critical period hypothesis)是一个长期存在争论的假说,关于人是否存在一个语言学习的关键年龄段。 该假说一般认为,存在一个理想时期更容易受语言环境影响从而
罗伯特·威尔基Robert Leon Wilkie Jr. (born August 2, 1962) is an American lawyer and government official serving as the United States Secretary of Veterans Affairs. He was co