In a healthy ecosystem, the populations of each species tend to from year to year a. Grow
b. Shrink
c. Shrink and grow
d. Disappear

Which detail belongs in paragraph 5 to support the main idea of the paragraph? a) places to receive acupuncture are increasingly easy to find all across the united states. b) not everyone is necessarily fond of acupuncture; some patients prefer other methods of physical therapy. c) even though acupuncture is a popular chinese treatment, it has grown popular around the world. d) most of the adverse effects of acupuncture that have been reported do not derive from the procedure itself but from improper application.

A(n) __ clause should always be separated from the rest of the sentence by commas

Find the center and the radius of the circle with the equation: x^-2x+y^2+4y+1=0