Darwin focused on studying specific species on the galapagos islands and other places and observed
a. the genetic makeup of the individual species
b. that fossils tell us about the past
c. similar species in different areas with unique traits
d. how individuals grow in numbers

Explain the source of radioactivity in uranium in earth’s crust by which it produces nuclear radiation

Methane gas created by a cows flatulence especially in a large herd is a greenhouse gas. true or false.

When does a spring tide occur? question 9 options: they occur when the sun, moon, and earth are aligned. in spite of their name, these tides occur twice a year in the spring and fall. they occur on the date of the vernal equinox each year, no matter what stage the moon is in. this is why they are called spring tides. they occur when the sun, moon, and earth are at 45-degree angles from each other. this happens once every spring. they occur when the sun, moon, and earth are aligned. in spite of their name, these tides occur all year long.