Answer:<u> Option D
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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.
Perception of pitch and sound intensity is the cocklear
Living things obtain and use energy so alive?
For this information to be true, that would mean freckles is a dominant trait, and to not have freckles is a recessive trait. So that means if even someone's genotype has both the freckle and the no freckle gene, their phenotype will be freckles.
Answer:
3) Temperature
4) gill covering opening and closing per minute
5)as temperature rises, the rate of gill covering opening and closing per minute increase until the temperature reaches 27℃ where the rate decreases
Explanation:
4) you can adjust and control the temperature in an experiment
5) you can't control the gill opening and closing rate