A.technology
B.chest
C.church
D.cheerful

A. workers often got iii because of the poor working conditions
B. companies were free to put out any products they wanted to
C. many people were killed by the dangerous products
D. industries were not as careful in management as they are today

A. the fact that viruses have been known to mutate
B. the fact that a cancer-immune individual may lose his immunity
C. the fact that production of human cancer cells might be due to a genetic factor
D. the fact that man is host to many viruses