When you take blood pressure, it is expressed in a fraction. The top number of that fraction is systolic pressure- the amount of pressure in your arteries during contraction of your heart muscle... I hope this helped! :)
A community which is a ecosystem
Species have changed over time ti adapt to their environment
Microbes cause infectious diseases such as flu and measles.
https://microbiologyonline.org/about-microbiology/microbes-and-the-human-body/microbes-and-disease
Answer:
Formation. When the solar system settled into its current layout about 4.5 billion years ago, Earth formed when gravity pulled swirling gas and dust in to become the third planet from the Sun. Like its fellow terrestrial planets, Earth has a central core, a rocky mantle and a solid crust.