S6. According to the passage, why are students of the same achievement level grouped together

A．To correct a common misunderstanding about grasshoppers.
B．To help explain how well grasshoppers can jump.
C．To compare the size of grasshopper with that of other insects.
D．To show how quickly grasshoppers respond to danger.

A．Check to see if anyone lazes out.
B．Do the group members’ work.
C．Check to see if it’s done correctly.
D．Check to see if everyone is there.