The ? era featured the longest periods with no life forms on Earth. A Palezoic
B. Precambrian
C. Cenozoic
D. Mesozoic

Put the following steps of the convection process in the correct order. 1. gravity pulls cooler matter downward. 2. the matter expands and decreases in density. 3. an up-and-down flow of matter produces a convection current. 4. matter is heated. 5. warmed matter is forced upward. question 2 options: a) 4, 2, 5, 1, 3 b) 2, 4, 3, 1, 5 c) 3, 2, 5, 4, 1 d) 1, 4, 2, 5, 3

Body systems are not completely independent they integrate and work together describe one example of the integration between body systems

If a strand of dna has 35% thymine. what is the percentage of cytosine, adenine, guanine?