Prototypes are used to a. communicate a solution. b. test the operation of a product. c. identify a need. d. research a problem.

Which of the following is not a major characteristic used to identify minerals? a. hardness c. density b. magnetism d. luster select the best answer from the choices provided a b c d i know it is not d

Can someone me with this and tell me what’s fracking and what does it have to do with carbon, carbon dioxide, or fossil fuels?

Natural selection changes allele frequencies because some survive and reproduce more successfully than others.