The failure, till now, to produce an effective aids vaccine may be due to the fact that the causative agent mutates continuously thus it is practically impossible for the body immune system to take advantage of vaccination.

a. true. b. false

A. True.

Explanation:

The AIDS virus may constantly change it's form in the host body by mutating. The body immune system becomes unable to produce antibodies which can fight against these mutated cells.

Also, the vaccination used for the purpose of immunization will not be able to combat will the causative agent in the body of the host. As the vaccine contains the microbe which can fight against the virus present in the body. But as the virus is changing it's form the microbe may not be able to compete with the virus. Hence, the use of vaccine will become useless.

surface mining destroys mountain tops, landscapes, forests and wildlife habitats. on top of that, it leads to soil erosion and destruction of agricultural land. the landscape changes can also disrupt river channels and streams, which leads to flooding. which, can destroy plant life and other animals as well.

explanation:

the eggs of the insects should be the first thing collected at the scene.

false