B. It provides information about why certain measurements are made in an experiment
From experience, to be able to have background research helps in the design of an experiment because it would tell you what is being measured in a experiment. Without the background information, my whole class got lost on what to do until my teacher told us what we had to measure and how we could measure the experiment.
Answer:
only 30% of total energy will be useful ..
So, Useful energy =

13.5J energy is useful
I think B is the correct answer. Answer choices C & D are about dolphins, but they do not have anything related to negative effects surrounding human and dolphin interaction. A, on the other hand, may seem like a good choice, but then again, the answer is too vague.
Answer:
C) When common lands are protected, land degradation slowly disappears.
Explanation:
I think a frameshift mutation that occurs very early in a protein sequence would have an effect on the structure of the protein such that the primary, secondary, and tertiary structures would be altered. A frameshift mutation occurs when a protein is drastically altered because of an insertion or a deletion. Insertions and deletions cause a change in the length of a gene, which causes a shift in the codon reading frame.