Because if we use too much coal we are wasting fossil fuels and burning coal hurts the environment so the alternative energy sources provide clean energy
Answer: 3. They were born of one fertilized ovum.
Explanation: A zygote is formed
when an egg is fertilized by a sperm. The zygote then undergoes a mitotic division into two and each half will further develop into a separate embryo. The two embryos formed will develop into identical twins.
<span>An atom that has gained or lost electrons is called an ion</span>
