Really, none of these answers are good. leukocytes are the body's general immune cell, and lymphocytes are a type of leukocyte. Antibodies are only used when fighting an infection that your body already has experience with, so I'm guessing it you have to pick from these answers, its "lymphocytes", but it's not really the best answer.
Lack of clean water is able to complicate health. This could easily cause dehydration in children and adults. If someone is dehydrated, they won't be able to function properly and if they stay like this for long, this can cause a risk of death. Lack of clean water can easily turn into hygiene problems because the child wouldn't have a way to clean themselves or even do something as simple as washing their hands. This can transfer many bacteria only making the children catch illnesses. This, therefore, would prevent them from learning. This also goes for teachers because if the teachers do not have proper hygiene, they won't be able to teach. Once again this would affect children as well because children wouldn't have anyone to learn information. This would result in a bad education.
1) oxygen. 2) bone size 3) inner core, outer core 4) 10
