Answer:
Explanation:
It is estimated that the Precambrian Era lasted between 3.9 and 4 billion years. Many scientists believe that this era accounts for 90 percent of the world's history.
Answer:
The options are
A) they may affect several populations in an ecosystem
B) they cannot be caused by human activity
C) they affect food chains but not food webs
D) They have no effect on living organisms in an ecosystem him
The answer is A) they may affect several populations in an ecosystem
Explanation:
Environmental changes include deforestation and climate changes. Organisms depend on their habitat and climatic conditions for their survival because it determines their food availability too.
When environmental change occurs they may affect several populations in an ecosystem.
D. flammability
is a chemical property
The Rock Cycle is a group of changes. Igneous rock can change into sedimentary rock or into metamorphic rock. Sedimentary rock can change into metamorphic rock or into igneous rock. Metamorphic rock can change into igneous or sedimentary rock.
Igneous rock forms when magma cools and makes crystals. Magma is a hot liquid made of melted minerals. The minerals can form crystals when they cool. Igneous rock can form underground, where the magma cools slowly. Or, igneous rock can form above ground, where the magma cools quickly.
Answer:
D
Explanation:
it just makes sense to me
