Rhesus factor is an antigen present on the surface of red blood cells of Rhesus positive individuals. Rhesus positive (Rh+) is dominant to Rhesus negative (Rh–). A mother with Rhesus negative blood gives birth to a baby with Rhesus positive blood and there are concerns that subsequent pregnancies will trigger an immune response. What is a possible explanation for why subsequent pregnancies could trigger an immune response?

the electromagnetic spectrum includes, from longest wavelength to shortest: radio waves, microwaves, infrared, optical, ultraviolet, x-rays, and gamma-rays.

try using substitution:

x + y - 6 = x - y. (i'm not giving you the exact answer). since 0 = x - y, then sub 0 in the equation with x - y. combine your like terms, and then use inverse operations, and you'll have your answer.

: -)

the answer is c. altitude. hope this ! #brainiac