what element was poisonous to the first forms of life on Earth until they evolved to take advantage of it by using cellular respiration.

Hree steps to answering test questions correctly include a. underlining, repeating, reading c. reading, undoing, eliminating b. reading, underlining, erasing d. reading, underlining, eliminating

The personal identification number that students need to apply for federal student aid

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.