<span>B. es
</span>
We use "es" to refer where someone is from.
The primary and most significant greenhouse gas emitted from human activities is carbon dioxide. Burning of fossil fuels is the major cause of increased carbon dioxide emission.The burning of coal, oil, and natural gas is an important energy source to produce electricity.
Because in that way we keep thinking about them. How can you forget something when you're thinking about it?!
