As my memory serves me well, innovations like the production of gunpowder, tea, and silk are usually attributed to D. China
Answer:
Demographers study the growth and decline of human populations, and urban planners plan for the futures of cities (e.g. electricity, water, and transportation needs). Demographers and urban planners would benefit from working together to help solve difficult problems in society and to help plan for the future. A demographer would be very helpful to urban planners as they plan for the future of a city. For example, an urban planner would want to have an idea of the population growth in the city, or of the average growth rate in other cities, when planning for the city's future transportation, water, and electricity needs. Demographers and urban planners are important to each other! They help each other plan for the future of society
Explanation:
They are electromagnetic waves because mechanical waves have to be physically created by something, while electromagnetic waves are just emitted without any effort or force.
Question 2 ; the only star that is located in our solar system is the sun
