Answer to Question 1
Ethanol is a gasoline additive that can reduce the amount of oil used, however it is a hydrocarbon, so burning it produces carbon dioxide, however it is equivalent to the carbon dioxide absorbed by the plant during growing, so the net effect is carbon neutral in the long term. Negative impacts include agricultural land taken out of production for food, water and fertilizer requirements; single crop farming requires use of increased pesticides, and there can be loss of wildlife habitat.
Answer to Question 2
A barrage dam traps water from incoming tides behind and uses it to generate power by releasing the water through turbines.
Large-scale impacts of the (a) positive, and (b) negative phases of the North Atlantic Oscillation.
Gasoline prices
Nonverbal communications convey strong, powerful messages that may be negative or positive.
The ethanol molecule showing two carbon atoms, six hydrogen atoms, and one oxygen atom.
How to find two positive angles less than 360° for a reciprocal trigonometric function (secant)
Will Posting Nutritional Content in Restaurants Have a Positive Impact on the Obesity Epidemic?