Which of these statements about the atmosphere is correct?
(Mark the one best answer.)
O A The amount of each gas in the atinosphere is fixed and cannot change.
OB The amounts of greenhouse gases in the atmosphere can change.
O C Most gases in the atmosphere are greenhouse gases,
OD Most gases in the atmosphere are required for animal life.

Which of the following types of stars is most likely to end up as a supernova? in graph a, the curve peaks at 800 nm, in the red section of the visible light spectrum. in graph b, the curve peaks at 550 nm, in the green section of the visible light spectrum. in graph c, the curve peaks at 450 nm, in the blue section of the visible light spectrum. in graph d, the curve peaks at 300 nm, in the violet section of the visible light spectrum. a b c d

Consider the venn diagram of plant reproduction. where in this image, areas a - d, would you insert the picture of the orange lily?

The earth's oceans are made up of chlorine, and trace elements. a) carbon, oxygen b) oxygen, silicon c) hydrogen, oxygen d) nitrogen, oxygen