According to the chart, what would most consumers find to be the biggest obstacle to using wind or solar power?

Identify the youngest layer in the figure ( have to click one letter)

According to the article about the zhou dynasty, this dynasty was broken into different eras because its capital changed from place to place. how many different eras were there in the zhou dynasty? a. two b. six c. ten d. fourteen

Who were the kelvin-rus? describe who influenced them.