In order for a scientific explanation to be valid, it MUST be based on evidence from _[blank]_. a. hypotheses of scientific experiments
b. a credible scientific journal
c. the latest scientific research
d. observations of the scientific investigation

According to the big bang theory, after the "bang," the universe remained dark until about  300,000 yearsone billion yearsthree minutesthree billion years  later, when neutral atoms began to form.

Some mining processes involve removal of large areas of earths surface in the mined region this practice causes severe environmental damage by allowing which natural process to accelerate in the affected areas? a. precipitation b. erosion c. migration d. condensation

The carbon cycle is best defined as a process in which a. carbon changes from inorganic forms to organic forms and back b. carbon is changed into other elements such as oxygen or nitrogen c. carbon is continually created from the sun’s energy by plants d. carbon is consumed and regenerated from other elements such as oxygen and nitrogen