Experiments have shown that adult human hearing is most sensitive in the frequency range of the sound of a human baby crying. Based on the threshold of audibility curve shown for an adult male shown below, into which frequency rang
does most babies' crying fall?
20
decibels (dB)
80
-100
50
100
5000
10000
500
1000
Frequency (Hz)

Apopulation of deer mice was introduced into a desert ecosystem. being dark-colored, the deer mice stood out in the sand and were easy prey for predators. over a few years, the color of the mice changed from dark brown to light brown. what role does natural selection play in this example? a. the change of color camouflaged them, which them hunt better. b. the change of color enabled them to regulate their body temperature. c. the change of color allowed them to hide better from predators. d. the change of color made their bodies tolerant to the harsh desert sand. e. the change of color allowed them to deflect the excessive heat.

Jerrold has to buy 12 copies of a textbook which costs $36.25 per copy. how much must he spend for them?

Children learn the values, behaviors, and attitudes that will influence their lives through