What is used in compost bins to break down the living material?
a) fire
b) chemicals
c) anaerobic bacteria
d) grass cuttings

A60-tooth gear is connected to a 72-tooth gear.if the smaller gear turns 12 times,how many turns does the larger gear make?

What are the 3 types of artificial cloning

Which of the following types of pollution is most responsible for large numbers of deaths worldwide because of unsafe drinking water? (a) nutrient pollution (b) thermal pollution (c) pathogen pollution (d) sediment pollution