D.transverse waves move perpendicular and longitudinal waves move parallel to the direction of energy movement..
No light does not need medium to travel.Its an electromagnetic(EM) wave.All EM waves travel independent of medium. In contrast mechanical waves need a medium,sound waves,shock waves are mechanical and they need medium to transfer energy or travel.
Weeds are very important agronomically because they reduce the yield of crops in three ways: by competing with the crop for water, light and nutrients, by interfering with crop harvest, and by contaminating harvested products with weed seeds and toxins. Weeds can reduce yield up to 50% and are responsible for millions of dollars in crop losses each year.
It’s biotic factor would be competition as Competition can be defined as an interaction between organisms or species, in which the fitness of one is lowered by the presence of another.
Answer: D Minarel extraction cannot be done in ways that does not completely destroy the environment
Explanation: Hope this helps !!