(Question)
Answer the question below: A main sequence star that is very bright is not among the hottest or coolest stars? Assuming that: The hotter a main sequence star is, the brighter it is.
(Answer)
coolest

(Question)
Answer the question below: If an isomer has less branching than another isomer, it should have a higher or lower melting point? Assuming that: The more branching there is in isomers, the lower the boiling and melting points are.
(Answer)
higher

(Question)
Answer the question below: Jeff should add oil or gas to his engine to reduce the friction in its processes? Assuming that: To reduce friction, oil is added to the engine.
(Answer)
oil