Answer:
A. The cost of producing a kilowatt of power with fuel cell will be less than $30 in 2015
When an organism is buried quickly there is less decay and better the chance for it to be persevere. The hard parts of the organism such as bones, shells, and teeth have a better chance of becoming fossils that softer parts of the organism. HARD BONES.
Answer:
Sorry for disrespecting you but i don't know your language. I want to help but my problem is your language IM SO SORRY
<u>Answer: </u>The amount of heat released is 84 calories.
<u>Explanation:
</u>
The equation used to calculate the amount of heat released or absorbed, we use the equation:

where,
Q = heat gained or released = ? Cal
m = mass of the substance = 10g
c = specific heat of aluminium = 0.21 Cal/g ° C
Putting values in above equation, we get:
Q = -84 Calories
Hence, the amount of heat released is 84 calories.
I believe it is b. you only want to change one thing at a time so you know which one thing caused the effect