Who introduced the smoking of opium to the U.S.?

Science produces progress. An excellent example of this is Mendel's work in

(a) astronomy (b) archaeology (c) heredity (d) psychology

Katie wonders when she will first be able to hear her fetus's heartbeat through a stethoscope. You tell her that this should happen by the

A) fourth week of pregnancy. B) third month. C) end of the second trimester. D) beginning of the third trimester.