Answer:<u> Option D
</u>
Solar panels contain a very expensive element, i.e. silicon. This element is able to convert the solar energy into electric energy. The cost of the solar panel gets expensive because of this rare element. It is found in limited areas of the world. That’s why option D is correct. Coal is not used in solar panel, so option B is incorrect. Neither is wind energy, so option A is also incorrect. Water is also not used for exploiting solar energy, which makes option C a wrong answer.
Answer:
Earth's outer core is a fluid layer about 2,400 km thick
Explanation:
composed of mostly iron and nickel that lies above Earth's solid inner core and below its mantle. Its outer boundary lies 2,890 km beneath Earth's surface
It is the ribosomes that assist tRNA
Answer:
<h2>False</h2>
Explanation:
Natural killer cells (NK cells) are a type of lymphocyte and also a component of innate immune system. NK cells play various functions in immune system and they play a major role in the host-rejection in virally infected cells.
NK cells are activated in response to interferons and also by various other responses. NK cells work to by secreting IFNγ and TNFα. Natural killer cells play a very important role in early host defense against viruses.
Answer: to start what cycle
Explanation: