Avaccine
a. can be harmful because it contains pathogens such as viruses.
b. contains a changed pathogen, so the pathogen is no longer harmful.
c. provokes a response from the viral immune system.
d. all of the above

Lymphatic vessels remove excess fluid from tissues. often after mammexront( the surgical procedure to remove of all or part of a breast) the lymphatic vessels draining the arm are damaged. explain a consequence of this damage. what can be done to reduce the symptoms?

The intervention of extraterrestrials has been used to explain the bermuda triangle, a region of the atlantic ocean where ships and planes are frequently lost, leaving no evidence behind. how would this explanation best be characterized?

What are the doorways into and out of cells, attached to the membrane, and built in the rough er.