~someone answer asap~ which structures pump the blood from the heart? a. atria b. veins c. arteries d. ventricles

Which of the following is characteristic of the lytic cycle? a) viral dna is incorporated into the host genome. b) the viral genome replicates without destroying the host. c) a large number of phages are released at a time. d) the virus—host relationship usually lasts for generations.

The first step in treating water from a river or lake is usually

Witch form of birth control could people use without. altering hormonal systems or blocking sperm from fertilizing an egg