On the primitive earth, a great many hydrocarbon compounds were formed, mixed together in water, heated by volcanoes and lightning, etc.
(a great many hydrocarbon compounds; were formed; L:On the primitive earth) (a great many hydrocarbon compounds; mixed together; in water) (a great many hydrocarbon compounds; heated; by volcanoes and lightning)
a great many hydrocarbon compounds a great many hydrocarbon compounds a great many hydrocarbon compounds
were formed mixed together heated
L:On the primitive earth
in water
by volcanoes and lightning