Pls Help ASAP Chemical energy sources are often portable and provide large amounts of energy. Fossil fuels are one kind of chemical energy source. Most of the energy we use in the United States is generated by the combustion of fossil fuels. However, fossil fuel combustion adds greenhouse gases to the atmosphere, mostly CO2. One measure of the total amount of greenhouse gases that are emitted into the atmosphere each year is called a carbon footprint. Read this article to compare the carbon footprint of an average person in the United States to an average person around the world.

Knowing that greenhouse gases are contributing to climate change, how can we reduce our carbon footprint, particularly in the United States? Could hydrogen fuel replace fossil fuels in the future? Why or why not? Should the size of a person’s carbon footprint be limited by law? Why or why not?

1. the question asks the most appropriate, which seems to rule out "all of the above." your choice appears to be the correct one.

2. the protocol described is good for identifying correlation, but not cause and effect. for cause/effect, you need to devise a protocol that will assign the treatment (or not) to groups that have essentially the same "demographics" with respect to all the other variables. your choice regarding control group seems appropriate. random assignment of treatment (choice d) may be appropriate also. (i think you can argue that b and d are just different descriptions of the same method.)

3. d will randomize the birds, but may not guarantee there are 10 in each group. e will do both, so seems the better choice.

comment on question 2

based on the problem statement, it seems clear that confident, attentive drivers are more likely to use daytime running lights. so, the protocol might need to be devised in such a way that the lights would be turned on or off without the driver's knowledge. (an attentive driver will figure it out.) assigning a confident, attentive driver to a group required to drive without running lights might mess with his/her confidence and attentiveness. you don't want your experiment to do that. (nor do you want the experiment to subject a driver to greater risk of accident as a consequence of driving without running lights.) experiments involving human safety are always problematic.

the answers would be

the first one and the second one

< > according to newton's third law of motion, forces always act in equal but opposite pairs. another way of saying this is for every action, there is an equal but opposite reaction.< >

16

explanation:

the marks go by 4s