What's the smallest substance of a compound? ?

The authors use the word “backbone” in lines 3 and 39 to indicate that

Earth takes in thermal energy from the sun in a process called . sunlight strikes earth’s surface at different angles. this angle is called the angle of . btw its

How are 3-d printers useful in studying evolution? a. to color the fossils of organisms b. to create clones of extinct organisms c. to create replicas of fossils d. to prepare paper cutouts of organisms e. to study the composition of fossils