Is one way to develop active immunity to a disease.
a. chemotherapy
c. a vaccine
b. taking vitamins
d. all of the above

What is one disadvantage of desalination? a - the process kills fish. b - the process uses fuel that is expensive. c - the process makes water that is unsafe to drink. d - the process is too difficult to carry out in big cities. quick taking a !

Which of the following is a consequence of urban heat islands? increased precipitation downwind of the city? increased precipitation upwind of the city? decreased winds within the city? increased winds within the city?

Why reason best illustrates why hershey and chase chose to use viruses in their experiment?