Answer the following question: You are presented with the quiz "What are invaluable for soil health?"   But you don't know the answer, so you turn to your teacher to ask for hints. He says that "annelids are worms such as the familiar earthworm" and "earthworms are invaluble for soil health".   So, what's the best answer to the question?


 (a). bacteria;
 (b). annelids;
 (c). sharks;
 (d). Exfoliation;
 (e). bioaerosols;
 (f). plankton;
 (g). evaporation;
 (h). sunlight;
Answer:
(b).