Read the following passage and choose the option that be...

teachers can expect learners to acquire a certain grammatical structure after being led through a developmental sequence;

teachers cannot expect learners to acquire a certain grammatical structure which is too complex;

learners need a particular amount of time to internalize a certain grammatical structure;

as the learner's interlanguage develops, he will master structures in sequence;

learners go through a complex process of developing a certain grammatical structure.