Answer:
1. A massive star depletes its nuclear fuel; gravity overpowers the star; supernova occurs; core of star collapses
2. black hole; gravitational pull
3. The center of the Milky Way
Explanation:
Answer:
B
Explanation: First degree only makes the skin turn red
Warm air rises and eventually cools. Answer choice D.
Answer:
1. Water vapor condenses to form clouds.
2. Water falls as rain, snow, and sleet.
3. Water flows down mountains and hills.
4. Water joins streams or forms groundwater.
Biomass is the most used renewable source of energy in US in the year of 2009.
<h3><u>
Explanation:</u></h3>
In US, the country is very cold and use of wood and other plant products as chimney fuels, or in cooking and other purposes are very common. This is because being a temperate country, US has forests of conifers which are source of soft wood, ideal for burning.
Other sources of Biomass energy comes from the biogas, wood wastes, ethanol, municipal solid wastes and even biodiesel.
As a present day scenario, although coal and petroleum are still the most used fuels in US, but the use of renewable sources of energy has increased to twice the amount from 2010 to 2018.
