What gas important to life was absent from earth’s earliest atmosphere?
a.
nitrogen
b.
methane
c.
oxygen
d.
carbon dioxide

Which statement is always true? a. square bcdf is a rectangle. b. rectangle gjkm is a square. c. quadrilateral stpr is a trapezoid. d. parallelogram abcd is a rhombus.

Monthly water bills for a city have a mean of $108.43 and a standard deviation of $32.09. find the probability that a randomly selected bill will have an amount greater than $155, which the city believes might indicate that someone is wasting water. would a bill that size be considered unusual?

The number of branches on a tree demonstrates the fibonacci sequence. how many branches would there be on the next two levels of this tree? 13 | | | m branches