Car overheating but it has coolant

I have a 2004 Honda Civic Lx 1.7L and I lost my collar resovoir cap, would that cause a problem in my car overheating, I've made sure it has coolant and it's the right kind but it still overheats and I'm not sure if the cap is there to keep pressure or just to keep debris out.

Why do some parents allow their 4th grade daughter to wear mismatched clothing or have their hair unbrushed at school?

This little girl in my daughters class is poorly dressed, has unbrushed hair constantly, and has never had a academic award. Her mom was badly dressed too but her mom is a nurse? I work in Finance making 55k a year and I had on a business outfit and my daughter had on a aeropostale shirt, jeans, and converse shoes. I just don't get why some parent's want their child to be the weird kid and not a cool kid. I was popular in school and so was my husband. Her mom took her to school one day in what looked to be walmart sweats, a shirt with holes, and house slippers and left in a black honda civic. Why even bother taking your kids to school if you don't brush their hair or makr them brush their teeth? My daughter says that the girl has braces and has bad breath sometimes.