Question

choose a word to complete each sentence. write each sentence so it makes sense.

1. a leaf that has been ____ for millions of years is a fossil.

a. preserved
b. hidden
c. alive

1. most fossils are found in ____ rocks.

a. metamorphic
b. sedimentary
c. igneous

1. both __ and __ can preserve fossils.

a. plants and animals
b. dirt and water
c. ice and hardened tree sap

Explanation:

Question 1:

A fossil is a preserved remains of a once - living organism. A leaf that has been preserved for millions of years fits the definition of a fossil. "Hidden" doesn't convey the idea of preservation, and a leaf can't be "alive" for millions of years in the context of a fossil. So the correct answer is a. preserved.

Question 2:

Fossils are most commonly found in sedimentary rocks. Sedimentary rocks are formed by the accumulation of sediment, which can trap and preserve the remains of organisms. Metamorphic rocks are formed by the alteration of existing rocks due to heat and pressure, which usually destroys fossils. Igneous rocks are formed from the cooling of magma or lava, and it's very rare to find fossils in them as the high temperatures would destroy the organic material. So the correct answer is b. sedimentary.

Question 3:

Dirt and water (sediment and water) are common agents in the process of fossil preservation. Plants and animals are the ones being preserved, not the preservers. Ice and hardened tree sap are specific types of preservatives but the question is about the general agents, and dirt and water are more general and common in fossil preservation. So the correct answer is b. dirt and water.

Answer:

1. a. preserved
2. b. sedimentary
3. b. dirt and water