The corona is the part of the sun that we see from Earth
O releases mostly harmful UV and X-ray radiation
creates the sun's energy from nuclear reactions
is mostly made of helium atoms

Explain two reasons you think it is important for scientists to search for new ways to treat cancer

What was the land like over 500 million years ago? what was under the sea?

What can be said about farmers in highly developed countries? a) they have little or no negative impact on the environment. b) they practice subsistence agriculture. c) they are able to incorporate polyculture into their farming practices. d) they utilize organic farming techniques on a regular basis. e) they rely on large amounts of energy from fossil fuels.