Generally the most effective rebuttal to the counterclaim is to prove that the counterclaim is either false, or make it so that it sounds like it is not a big obstacle to the claim you are trying to make.
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Answer:
The most effective rebuttal to the counterclaim is,
There are several ways by which large school days help children, but spending time with friends and extracurricular activities also must be considered. They should not make the children restless.