Contemporary calculations have proven the accuracy of muhammad ibn musa al-khwarizmi’s calculations of what?.

In the image, layer a is the topmost layer. layer c contains fossils from the precambrian era. layer b contains dinosaur fossils, and layer a contains fossils of mammals. which two statements are supported by this evidence? 1. mammals lived before the precambrian era. 2. dinosaurs and mammals existed in the precambrian era. 3. dinosaurs evolved after precambrian organisms. 4. precambrian organisms evolved after dinosaurs. 5. precambrian organisms were the first life-forms to become fossilized, according to this sample.

How do you work out 21.3-8= show your working. plz

Essay questions may also be referred to as a. talk questions c. hard questions b. explain questions d. think questions