Older generations had more accurate health information, and people were more active.
Intra-uterine device(IUD) to prevent the fertilised egg from implanting itself in the uterine wall.
The correct answer is A (Automobiles).
Particulate matter is a complex mixture of extremely small particles and liquid droplets.
One of the major components of particulate matter is sulphate usually coming from sulphur dioxide found in exhaust fumes that have been produced by automobiles . Other components are nitrates , ammonia, sodium chloride and black carbon.
Other components of particulate matter come from dust, soot, smoke, industrial emissions.
Particulate matter is one of the most common contributor to air pollution.
Im guessing walking because you walk between classes.
The first line of defence (or outside defence system) includes physical and chemical barriers that are always ready and prepared to defend the body from infection. These include your skin, tears, mucus, cilia, stomach acid, urine flow, 'friendly' bacteria and white blood cells called neutrophils. Hope this helps.
