A vaccine works by training the immune system to recognize and combat pathogens, either viruses or bacteria.
Answer: Atoms were created after the Big Bang 13.7 billion years ago. As the hot, dense new universe cooled, conditions became suitable for quarks and electrons to form. Quarks came together to form protons and neutrons, and these particles combined into nuclei.
<span>Rice pudding would be an example of a heterogeneous mixture.
A heterogeneous mixture means that different constituents of a mixture can be identified. Rice pudding consists of rice suspended in a cream. It is possible to identify the grains of rice and the creamy part of the mixture.
A homogeneous mixture looks the same throughout--you cannot identify individual parts or ingredients. The parts of a homogeneous mixture are said to be uniformly distributed. Rainwater and air are examples of homogeneous mixtures.</span>
The correct answer is - one-half.
In the past century, the deforestation of the rainforests in the world had been devastating, and it is estimated that approximately one half of the tropical rainforests have been destroyed.
The reason for the large scale destruction of the rainforests is mainly because of clearing space for agriculture and for spaces where the cattle can graze. Unfortunately, the people that live the regions where the tropical forests are, are not well educated as to how to manage the land, and a big problem is that the soil of the rainforests is only good for 2-3 seasons, because it spends and erodes very quickly. Because of that, people just continue to clear more and more of it, thus leaving destroyed forest and destroyed soil behind them, without taking in consideration the long term effects.
Answer:
b. Capillaries; veins; arteries
Explanation:
Capillaries are the blood vessels with very thin walls. They serve as a site for an exchange of substances such as respiratory gases, nutrients, and toxins between the blood and the cells of the tissues. Veins are the blood vessels that mostly pick the deoxygenated blood from the body cells and deliver it to the heart for oxygenation. On the other hand, arteries are the blood vessels that mostly carry the oxygen-rich blood. They pick the oxygenated blood from the heart and deliver it to body cells. Therefore, veins carry blood towards the heart while arteries carry it away from the heart.
