In second language acquisition, input and output are necessary but can not successfully explain how learners acquire their target languages. This paper, hased on an analysis of the limitation of input hypothesis and output hypothesis, argues that maximized and optimized intake is the core of second language acquisition, as well as a key factor to improve teaching efficiency. Intake, which includes simplifying, inferencing, structuring and restructuring, is a complex psychological process. Factors which affect intake include linguistics factors, l...
