7Lakmal A & Dawson P. Motivation and cognitive load in the flipped classroom: definition, rationale and a call for research [ J ]. Higher Education Research & Development. 2014:1 - t4.
8Krashen S. The Input Hypothesis: Issue and Implications [ M]. London: Longman. 1985.
9Swain M. Communicative competence: Some roles of" comprehensible input and comprehensible output in its development [ C ]// In Gass S & Madden C (eds.). Input in Second I,arlguage Acquisition Rowley, M A: Newbury House. 1985:235 -253.
10Long M. Native speaker/non-native speaker conversation and the negotiation of comprehensible input [ J]. Applied Linguistics. 1983, (2) : 126 - 141.