Why are index fossils helpful? A. Since they are only from a specific time period, the rock layer they are found in, and all
fossils within it, must also be from that time period. This helps scientists date fossils.

b. They are the only radioactive fossils and so help scientists find its specific age

c. They never break down, like other fossils, so they are a permanent glimpse into
history.

What is an animal that lives by preying on other animals

Acceleration is a direct result of a.) balanced forces b.) unbalanced forces c.) gravity d.) velocity

For the strategies below, decide whether they are best described as demand-side solutions or supply-side solutions to meeting human needs for fresh water. remember that a demand-side solution reduces demand for fresh water, whereas a supply-side solution increases the supply of fresh water. (a) damming a river to create a reservoir (b) desalinating seawater (c) a nation invading a neighboring country to access their rivers (d) raising water prices for consumers and businesses (e) providing tax breaks for companies that use less water (f) replacing inefficient irrigation with more-efficient drip irrigation to grow crops (g) requiring low-flow showerheads in all new homes