(2) These students are not mature enough.
(3) Everyone has the same IQ, but some people are more diligent, so they can stand out. If a person is not diligent, even the cleverest brain will become dull. Modern society is a competitive society. Only by working hard, studying hard and making yourself smarter can we keep up with the times.
So what is diligence? As the name implies, diligence means spending twice as much time studying. Of course, we should also combine work and rest.