The systems of earth have both internal and external sources if energy. which of the following are internal sources of Earth's energy? I. Fusion reactions between hydrogen atoms in Earth's core
II. The decay of Earth's radioactive isotopes
III. the gravitational energy from Earth's original formation
IV. heat that is generated when water molecules spontaneously split in Earth's oceans

a. I and IV only
b. I, II, and III only
c. II and IV only
d. II and III only ​

b is the correct answer

some fungi obtain their nutrients from a living host (plant or animal) and are called most biotrophic fungi have fairly narrow host ranges—they are specialized on a limited called rhizomorphs that allow the fungus to grow from one tree to another. ascospores are formed inside a sac-like structure called an ascus. so your answer is a

the correct answer is 4) heat and pressure

metamorphic rocks arise from transformation of existing rocks types, in a process called metamorphism. during metamorphism the original rock(prolith) change into metamorphic rock by heating (150-200c) and pressure of more than 1000 bar. the original rock can be sedimentary, igneous, or existing metamorphic rock.