What are the shortcomings of the study of homework in elementary school language nowadays

Too early to learn too many things, so young to start staying up late, as long as in elementary school to maintain a good behavior, will lack of imagination 2, schoolwork pressure, the child's childhood will be very miserable 3, schoolwork pressure, it is easy to affect the physical development of 4, sleep will certainly be very late, junior high school and then study is not too late, it turns out that there are a lot of later on in our class 1