Dr. bennett does an experiment that leads him to invent a machine that can turn salt water into fresh water. it is very slow and costly. he continues his research to improve on his original invention and finds a way to make it work more quickly and inexpensively.
which of the following ideas does this illustrate?
a. scientific research can be based on the results of previous experiments.

b. scientific research is only useful for inventing machines.

c. scientific research is always expensive and pointless.

d. scientific research is never based on the results of previous experiments.

Embryonic stem cells are cells derived from an embryo. these cells can be used to create new tissues for patients suffering from certain illnesses and disorders. which statement best summarizes why the use of embryonic stem cells could be seen as unethical? a. some people consider embryos to possess rights equal to those of fully developed human beings. b. extracting stem cells from embryos is a very energy-intensive process, which consumes resources that could be used elsewhere. c. embryos are difficult to obtain, so the monetary cost of using them for research outweighs their benefit. d. the process of extracting stem cells from embryos generates biohazardous waste that cannot be safely disposed of.