Which best describes what happens to a developing fetus during the third
trimester?
A. The external sex organs develop.
B. The limbs form.
C. The organs grow larger.
D. The eyes develop.

limbs form the baby has fingers, hands,arms, feet and toes. they can now open and close their fists and mouth

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds