Answer:
I'd say the answer is B. reflection of waves off smooth walls
Explanation:
Answer:
Explanation:
Dna is shaped as a double helix and has weak hydrogen bonds. They contain complementary base pairs (adenine and thymine) and (guanine and cytosine).
Hope this helps.
Answer: Vaccines give you immunity to a disease without you getting sick first. They are made using killed or weakened versions of the disease-causing germ or parts of the germ (called antigens). For some vaccines, genetic engineering is used to make the antigens used in the vaccine.
Explanation: Vaccines greatly reduce the risk of infection by working with the body's natural defenses to safely develop immunity to disease.