Which best characterizes the precambrian era?
a. abundant plants and animalsb. dinosaursc. small, one-celled organisms and primitive jellyfishd. extensive mountain building?

c: warm water flows from the western tropical pacific toward south america. that should be the right answer! hope it .

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.