Because it is for school related topics. Join a chat room that allows you to say as you wish. Like your mom would say: Their house, Their rules.
#1 would probably be:
a. focus the teaching of nutrition concepts at times when the children are eating
No, I do not think it is the best way for them to be efficient.
Coal mining causes massive land use, tailings (waste), pollution to the air and water, and the effects it can have on the workers mainly includes respiratory problems.
Some things that could happen to prevent pollution is to keep the area as contained as possible away from water outlets. Safer, environmentally friendly chemicals could be used instead of chemicals that pollute the air and water. Mining waste needs to also be properly disposed of and away from any water is could seep into.