Which statement best compares the melting point of butane (c4h10) with that of octane (c8h18)?

Which of the following describes a situation where competition between producers exists

Answer asap : ( a. how does mucus prevent the entry of pathogens? b. describe two ways white blood cells protect us from pathogens.

A40 kilogram skier starts at the top of a 12 meter high slope. at the bottom, she is travelling 10 meters per second. how much energy does she lose to friction