At which point in the life cycle of a star does nuclear fusion begin?
black hole
main sequence
nebula
protostar

Which best describes a rhinovirus? o a. a virus that causes a common cold o b. a protective shell around a virus o c. a tube the comes off a virus o d. a piece of dna transferred by a virus

Control of the body is accomplished by which of the following body systems? nervous system and circulatory system endocrine and repertory system circulatory and respiratory systems nervous system and endocrine systems

In general, characteristics that an organism survive and reproduce become more common over time. what mechanism of evolution causes this?