Science
crude oil is mostly made of which of the following?
a. greenhouse gas
b. hydrocarbons
c. carbohydrates
d. carbon dioxide

i think a) betsy can donate only blood to mark is correct because, mark and betsy have the same blood type. whereas nobody else has b+ blood so betsy can't donate to them.

the answer is d. exposing corruption in the church

the statements that apply here about binary star system are

"have stars that might appear to wobble"

"often have one star that is brighter than other"

a binary star is a star system consisting of two stars revolving around their common barycenter. systems of two or more stars are called multiple star systems.