How can scientists test their ideas about the origin of the universe if they can't physically interact with or study?

Which statement about the immune system is false? a. lymphocytes reduce inflammation, b. b cells remember specific pathogens. c. most white blood cells kill bacteria d. white blood cells are made in lymph nodes.

All ova contain sex chromosomes corresponding to: x y xx xy

The starting materials in a nuclear change have a total mass of 2.3465 x 10-27 kg. after the change, the resulting materials have a mass of 2.3148 x 10-27 kg. how much energy was released during the change? 2.85 x 10-12 2.08 * 10-10 j 0 211 * 10-10 j 8.56 * 10-43