The best answer is D because construction would be bad for the environment and take up space on the soil that is trying to be preserved. Also, for C, planting only one crop type in soil is not very beneficial to the soil at all. IT is best to plant multiple crops in the soil and move the crops to different parts of the soil each year when planting them.
Answer:
Plant is a producer in food chain
One half-life after a radioactive isotope is incorporated into a rock there will be only half of the original radioactive parent atoms remaining and an equal number of daughter atoms will have been produced.
A heterogeneous mixture composes of non- uniform components, so the concrete would be the answer, because you can tell the components from one another.
