The decline in muscle mass with age is due to Both a decrease in muscle fiber size and a decrease in the number of muscle fibers are correct. None of these answers is correct. a decrease in muscle fiber size. a decrease in the number of muscle fibers.

(select all the correct choose each statement that is scientific. - the opinions of randomly selected participants in a survey prove the idea that global temperatures are not increasing on earth. - the universe's average temperature and rate of expansion support the idea that it began as one super-dense and hot mass 13.8 billion years ago. - ocean tides are caused by the uneven gravitational pulls of the moon and sun on different parts of earth. - human life is more valuable than other forms of life on earth because humans are more intelligent than other organisms.