Definition of natural and while numbers

The physical processes that create most of earth's physical features, including mountains, are known as

In the following diagram, four different index fossils are labeled: which of the labeled fossils comes from the oldest organism? a b c d

Which of these is a drawback of using natural gas? a. it is fairly safe for use in homes. b. it burns more cleanly than crude oil products. c. scientists have developed new ways of extracting it. d. during its extraction, groundwater can be contaminated.