What does the author means by saying "gaining momentum on the Internet"

A．Mimicking is the most difficult task for the teacher and students as well.
B．The teacher has to explain to the students without taking up too much time.
C．The sessions are essential to the students' carrying out the particular activities.
D．Once the target of the activity is settled, nothing should change any mor

A．of the teacher to make clear to the students the relevance of the activity and the target
B．of the teacher to see the relevance of what they're doing and their own personal goals
C．of the students to understand the activity cognitively before they tackle something
D．of the students to identify clearly their targets before they do anything in class