Q: What is secreted by the cells surrounding spermatogonia to help sperm production? Choices: - estrogen - dihydrotestosterone - follicle stimulating hormone - testosterone A:
testosterone

Q: In addition to a vibrating electric field what does an electromagnetic wave consist of? Choices: - radiation field - molecular field - gravitational field - magnetic field A:
magnetic field

Q: When what common element forms single bonds with other atoms, the shape is tetrahedral, and when its atoms form a double bond, the shape is planar? Choices: - oxygen - hydrogen - silicon - carbon A:
carbon