The theory that earth's outer layer is broken into pieces that move slowly over earth's surface is known as convection true/false

Cells destroy body cells infected by a virus or bacteria.

Which of these substances does not protect against invaders in the nonspecific immune response? a. saliva b. mucus c. tears d. urine

Ascientist is designing an investigation to study the impact of invasive bird populations on local, native bird populations at backyard bird feeders. what population is most likely to be a control group for the investigation? amount of food number of bird feeders invasive bird populations local backyard birdfeeders without food