Is daily homework necessar2

Is daily homework necessary?
Many teachers assign homework to students everyday, and
they seldom doubt it. However, as far as I am concerned, it is
not necessary.
To begin with, not every teacher has classes everyday. For instance,
a chemistry teacher may have no class on Monday. It makes
students learn nothing new about chemistry that day. As a result, it
becomes unnecessary for the chemistry teacher to assign
homework. Because if the teacher still assigns homework, perhaps
the students will not have enough time to review what they have
learned that day, such as physics and biology.
In addition, everyone must have his or her own leisure time.
Students are not machines. They cannot work without any rest. Even
if a machine works everyday, its efficiency will become lower and
lower and refuse to work finally. So the teachers must let students
have some spare time, when they can play games, have a picnic and
do other things they like. It is good to children`s health.
Last but not least, assigning homework everyday is not a scientific
way of studying. Suppose you must do physics homework everyday.
After several weeks, you will probably think physics is so boring
that it no longer interests you. How could one learn physics well
under such circumstance? I think the only way to solve this problem
is not to assign physics homework everyday.
So from what has been discussed, one can reach only this
conclusion that daily homework is not necessary at all.