SORU: ?
Because of the complexity of second language
acquisition, it is not possible to investigate it from a
single perspective. Research in second language varies
according to the circumstances under which the
research is conducted. Circumstances vary firstly in
relation to the context in which second language
acquisition is taking place. ---- Secondly, the
circumstances will also vary depending on whether the
language being learned is a second or foreign language.
Thirdly, they may vary according to the age and other
characteristics of the learners.
Which of the following completes the paragraph?