Answer:
Deforestation
Explanation:
Erosion may occur when deforestation is in place, it sweeps land into the rivers. If this isnt the answer then it might be all of the above
2.1 a) nectar b) to produce seeds c) pollen is made in the ovary
Organelles must do their duties together and their activities must be coordinated I'm pretty sure.
(A nebula)
is a cloud of gas (hydrogen) and dust in space. Nebulae are the birthplace biths. There are different types of nebula. An Emission Nebubla such as Orion nebula, glows brightly because the gas in it is energised by the stars that have already formed within it.
(A star)
is a luminous globe of gas producing its own heat and light by nuclear reactions (nuclear fusion). They are born from nebulae and consist mostly of hydrogen and helium gas.
(red giant)
This is a large bright star with a cool surface. It is formed during the later stages of the evolution of a star like the Sun, as it runs
out of hydrogen fuel at its centre.
(red dwarf)
These are very cool, faint and small stars, approximately one tenth the mass and diameter of the Sun. They burn very slowly and have estimated lifetimes of 100 billion years.
(white dwarf)
This is very small, hot star, the last stage in the life cycle of a star like the Sun. White dwarfs have a mass similar to that of the Sun, but only 1% of the Sun's diameter; approximately the diameter of the Earth.
(Black holes)
are believed to form from massive stars at the end of their life times. The gravitational pull in a black hole is so great that nothing can escape from it, not even light. The density of matter in a black hole cannot be measured.
The simple answer is that in a battery the chemical reactions that produce the electrical current are produced from materials that are already in the battery itself, whereas in a fuel cell, the reactants, almost always Hydrogen and Oxygen are fed to the cell like an external fuel.
. However, while a battery makes electricity from the energy it has stored inside the battery, a fuel cell makes its electricity from fuel in an external fuel tank This means that while a battery may run dead, a fuel cell will make electricity as long as fuel is supplied. For hydrogen fuel cells, hydrogen is the fuel and it's stored in a tank connected to the fuel cell. When hydrogen in the tank runs low, you refill it, or replace it with a full tank.
