What three things have power home factories and cars in the past hundred years​

If someone could do the first couple, just so i can see how it's done that would be great! 20 points. complete a dichotomous key for the 10 leaves on the common leaves sheet. the chart provided here allows for 11 pairs of statements. depending on how you build your dichotomous key, you may or may not need all of them, or you may need to add some.

Which of the following represents the chemical reaction of hydrazine and hydrogen peroxide to produce nitrogen and water? a. nitrogen + hydrogen peroxide → hydrazine + water b. nitrogen + water → hydrazine + hydrogen peroxide c. hydrazine + hydrogen peroxide → nitrogen + water d. water + hydrogen peroxide → nitrogen + hydrazine

If a robot fixed another robot is it a engineer or doctor?