some macroinverebrates like mayflies are sensitive to pollution or low dissolved oxygen. if these organisms are present, then the stream can be considered a healthy stream. mayflies would be considered a(n)

Viruses can be transmitted through air, water, food, insect bites, and direct skin contact. once a virus gains entry into the body, it invades a host cell in order to? a. synthesize antibodies for defense b. deactivate the host cell's defenses c. access cell processes for reproduction d. metabolize host proteins and grow