Do sponges have of appendages jointed, not jointed, or absent

J. j. thomson’s experiment disproved the theory that an atom

How do the kidneys affect homeostasis

According to an observer on earth, planet x is stationary. maria and samir depart earth on their spaceships at the same time, each flying at 0.5c. maria flies toward planet x and samir flies in the opposite direction. according to maria, her voyage to planet x takes 9 years. how many years does maria's voyage take according to samir?