You are presented with the question "Viruses are so small that they can be seen by what?" and the following answer choices:  - focusing a lens  - A computer  - looking close  - rays or beams  - sunlight  - bending light rays  - seeing smaller  - tuning eyes  Now knowing that viruses are so small that they can be seen only with an electron microscope and once the camera is tuned with the microscope, the focusing depends on the microscope lens, choose the best answer.
focusing a lens

You are presented with the question "What creates active immunity from a parasite?" and the following answer choices:  - Cooking  - memory cells  - alpacas  - peachleaf willow  - Allergies  - mammals  - an organism's body  - animals  Now knowing that active immunity results when an immune response to a pathogen produces memory cells and if the parasite causes harm, it is a pathogen, choose the best answer.
memory cells

You are presented with the question "When the body is hot, the skin accumulates what?" and the following answer choices:  - heat energy  - nutrients  - disease  - heat  - hair  - moisture  - evaporation  - health  Now knowing that when the body is hot , sweat is produced to cool the body and sweats Sweats are products that cause moisture accumulation on the skin, choose the best answer.

moisture