They were studying the effects of acid rain on different aquatic organisms
Answer: A. virus strains multiplied in cell cultures
A cancer causing gene is caused by a mutation in a gene.
The answer is Practical Intelligence. Practical intelligence is the consequence of an exploratory hands-on working style that prompts particular learning. Practical intelligence is the capacity that people use to locate the best fit amongst themselves and the requests of nature.
It is a form of natural selection called sexual selection.