Ddt was a highly effective insecticide developed in the 1940s. ddt was so good at killing mosquitoes and reducing malaria that its inventor, paul muller, won the nobel prize. but in the 1960's it was discovered that ddt is taken up by algae in the water, increasing in concentration at each step of the food chain, because the pesticide remains in the fat tissues of organisms. the ecological problem that resulted from ddt use is called a) biohazard. b) bioremediation. c) biomagnification. d) food chain interruption.

What was dr. willem johan kolff’s first step in using the scientific process to invent the hemodialysis machine? he built the machine and tried it with various patients, collecting data about its effectiveness. when a patient’s kidneys failed, he wondered if it would be possible to perform kidney functions with an external machine. he researched and collected data about numerous patients who exhibited symptoms of kidney failure. he drew conclusions from studies of various symptoms of kidney failure, and drew a design for the ideal external blood-processing machine.

Sara goes on a slingshot ride in an amusement park. she is strapped into a spherical ball that has a radius 3*10^2 of centimeters. what is the volume of air in the spherical ball? use this formula: volume of a sphere=4/3pi,r^3 , where r is the sphere’s radius.

How have high taxes on tobacco products impacted the number of people who use them? a. the number of tobacco users has increased. b. the number of tobacco users has decreased. c. the number of tobacco users has not changed. d. the number of adolescent tobacco users decreased, while the number of adult users increased