Plants need bacteria in order to take up and use which element? a. carbon, b. oxygen, c. nitrogen, d. hydrogen

The answer is nitrogen. Plants cannot use atmospheric nitrogen directly. Nitrogen from the air must be converted into the different form so plants can absorb it. Thus plants need nitrogen-fixing bacteria to convert atmospheric nitrogen into ammonium, which is available for plants to absorb it.

We can use solar powered cars or ride bikes instead of cars that burn fossil fuels

Humans can affect weathering and erosion in several ways.  humans cause  increases in acid rain and pollution, which increase the amount of  weathering  agents in the air and water, and then on land.for an easy answer: 1) acid rain2) pollution