<span>According to the nebular theory stars are formed in which sequence:
a. Interstellar clouds - "nebula" is a Latin word which means clouds. These clouds start to form and are composed of gases like hydrogen and helium.
b.Clumps - as the gases start to form and come together they form clumps of gases that are highly concentrated and they start to grow.
c. Gravitational forces - when clumps have grown into big sizes the gravitational forces that are found within it increases and are converted into kinetic energy of fast-moving particles that continuously bump into each other and create or generate heat.
</span><span>
d. Nuclear fission - as the clumps keep on colliding and creating heat (18 million degrees Fahrenheit), nuclear fission begins.
e. Outward pressure from the nuclear fission prevents the collapse of the gases, stabilizing the gases eventually creating a star. </span>
Answer:
The correct answer would be Option C, Multipurpose Trees.
Explanation:
With the advancement in industries and other areas of technology, the rural areas have become so much polluted. So the sustainability of the rural areas is doubtful. The air in the rural areas have become polluted and needs measures to prevent it from harmful consequences of the industrial advancements. Along with industries, the air pollution is also added through vehicles discharge, waste disposal, etc also contribute towards the non sustainability of the rural areas. So to overcome all these problems, the best solution is to grow the multipurpose trees in the rural areas as much as possible to increase the sustainability of these areas. With the plantation of trees, the problem of pollution will be controlled and thus make these areas sustainable.
I believe the biggest space mission of the twenty-first century will be a manned mission to Mars, and the colonization that follows. This is the stated goal of several nations, companies, and individuals, all with considerably deep pockets. This mission will not only be a huge leap forward in space exploration, it will usher in a new era in human history in which the human race is an interplanetary civilization, a natural milestone as humanity continues to progress and advance.
Significant challenges are many and overwhelming. In terms of getting to mars, we need efficient, powerful propulsion systems and a spaceship that can not only accommodate a full crew for a mission that would likely last years, but withstand the various hazards that a long trip through space and entrance into the Martian atmosphere will entail. In terms of colonization, significant challenges will include establishing efficient and frequent travel/transport between the planets, and in the longer term, the necessity to terraform the planet (make it more like Earth) so that humans can more easily live there.
The carbon is among the most abundant element found in the living organisms. The carbon enters the food web through the producers via the process by which they make their food, which is known as photosynthesis. The plants during the process of photosynthesis, take in carbondioxide, water and capture the sunlight to make ATP. The carbon from all these elements enters the producers and then is passed on from one trophic level to another.
Hence, the blanks can be filled with 'producers, and photosynthesis'.