Index fossils are used to determine the relative ages of rock and fossils and are also used to define the boundaries between geologic periods.
<u>Option: A</u>
<u>Explanation:</u>
The fossils which are recognized as fossils guides or indicator fossils are used to classify and recognize geological or faunal periods, termed as index fossils. It must be of short vertical reach, wide geographic distribution and swift patterns in evolution. It helps to assess the rock layers ' age and helps to date other fossils found close and around them. For an instance, Ammonites were abundant in the Mesozoic period between 245 to 65 mya, they have not been found after the Cretaceous era, as they became endangered during the K-T extinction (65 mya).
B Ik it all just know who they’ll you
The distance of the galaxy is 32.86 Mpc.
Using the hubble law, v = H₀D where v = apparent velocity of galaxy = 2300 km/s, H = hubble constant = 70 km/s/Mpc and D = distance of galaxy.
Since we require the distance of the galaxy, we make D subject of the formula in the equation. So, we have
D = v/H₀
Substituting the values of the variables into the equation, we have
D = 2300 km/s ÷ 70 km/s/Mpc
D = 32.86 Mpc
So, the distance of the galaxy is 32.86 Mpc
Learn more about hubble law here:
brainly.com/question/18484687
The air inside becomes warmer, and that makes it LESS DENSE.
Less-dense air FLOATS in denser air. Since it's inside the balloon, it picks the balloon up when it floats.
