During a baseball game a pitcher threw a baseball, and the catcher, who was behind home plate, caught it. which is true about the pitcher when the catcher caught the ball?
a) he saw the catcher catch the ball first.
b) he heard and saw the ball at the same time.
c) he heard the sound of the catcher's mitt first.
d) he saw the catcher catch the ball, but did not hear it.

convex lenses are thicker at the middle. rays of light that pass through the lens are brought closer together (they converge). a convex lens is a converging lens. when parallel rays of light pass through a convex lens the refracted rays converge at one point called the principal focus.

.) the observation by semmelweis that more mothers died of childbed fever when their doctors also worked in the morgue