[问答题]
The following diagram s; ,kt x(r4jxv ekb)4lvhow)qun0,wt2ciw s a trophic level pyramid of energy.
1.Label the bottom (step A) and topmost steps (step D) of the pyramid to describe what types of organisms are present in the two levels.
2.State which trophic level can support the largest population of people, step A or step B?
3.Explain why animals at level D are most vulnerable to becoming extinct.
