_____ is a sexually transmitted infection that, in advanced stages, can attack major organ systems.
A) Rubella
B) Syphilis
C) Cystic fibrosis
D) Phenylketonuria
Question 2
At age 20 or 21, men stop growing taller because testosterone causes _____, which prevents the long bones from making further gains in length.
A) nocturnal emission
B) epiphyseal closure
C) osteoporosis
D) gynecomastia