填空题
Sociology is the study of language in relation to（）,such as social class, educational level and so on.
social factors
填空题 （）is the study of second and foreign language teaching and learning.
填空题 Psycholinguistics is the study of the mental processes that a person uses in producing and understanding language, and how humans learn （）.
填空题 Linguistics is the study of language as a system of human （）.
