19.下列那一組構造發育自胚胎的外胚層？
(A) liver, salivary glands, bones
(B) nerves, muscles, lungs
(C) bones, heart, kidneys
(D) skin, brain, nerves
(E) liver, skin, brain

1. 題目解析題目要求找出由胚胎的外胚...