What is the theory of evolution by natural selection based upon? A. the fossil record only B. observations of living organisms only C. on both the fossil record and observations of living organisms D. on neither the fossil record nor observations of living organisms

C. on both the fossil record and observations of living organisms

Explanation:

im sorry i wish i can but try google

productive most commonly means: achieving or producing a significant amount or result.

explanation:

productive can also mean:

these depend on how the word productive is used. most likely productive will mean   achieving or producing a significant amount or result.