20. The answer is 1 (Precambrian)
21. The answer is 4 (Pennsylvanian)
22. The answer is 2 (Bony Fishes, Dinosaurs, and Mammals)
23. The answer is 2 (Reptiles)
Answer: There are 3 major problems with hydrogen as a vehicle fuel, compared to gasoline. 1 - It takes a lot of energy to produce. You have to run a lot of electricity through water to break it down to hydrogen and oxygen. ... It's most useful form is liquid hydrogen, giving far more energy content than as a highly compressed gas.
Answer:
D. Spindle Fibers
Explanation:
During anaphase, the centromeres of each chromosome split and the mitotic spindle pulls the sister chromatids apart.
Calculating limiting and excess reactants?
Answer:
B
Explanation:
Animals derive energy by eating plants or animals and using cellular respiration to make ATP. Plants capture energy from the sun via photosynthesis and make sugar and oxygen. They can then use the sugar to perform cellular respiration to derive energy.
