What term do epidemiologists use to designate the rate or number of new cases of a disorder reported during a specified period?

Kristian’s parents both worked, and they pretty much left him to his own devices at home. Kristian came and went to middle school on his own, and only had to be back in time for dinner. In terms of parental relationships, teens with weaker relationships with parents are more likely to

a. save sex for marriage. b. engage in sex before age 15. c. stick with one sexual partner. d. delay sexual activity for at least 3 years.

What is the principal zeitgeber for land animals?

a. light b. the tides c. temperature d. barometric pressure