Why was the electric traffic signal invented?

According to douglass, what does the singing of a slave communicate? how does douglass feel about slave songs? in what way is slaves singing misinterpreted by some people? .

Explain how the roles of both working class and middle and upper class women changed during the industrial revolution. how did those changes lead to the women’s rights and suffrage movements?

What do most climatologists see as a major cause of rising global temperatures? a. earth's closer proximity to the sun due to its gravitational pull b. greenhouse gases produced by burning fossil fuels c. rising ocean levels caused by melting polar ice sheets d. water pollution cause by industrial waste