Which of the following is a pollutant that is measured by the air quality index?

Astructural difference between the trachea and esophagus that prevents the trachea from collapsing is the presence of: a) smooth muscle b) skeletal muscle c) respiratory cilia d) rings of cartilage

So i have a lot of answers answered but it says i still need to answer more questions. why is it doing that? how many questions need to be answered?

Which safe and legal options do teen parents have if they think they are not ready to be parents? check all that apply. leave the baby in front of someone's door. surrender the baby under their state’s safe-haven laws. place the baby for adoption. release custody to the baby’s grandparents. give the baby to a stranger.