A.3周歲 B.12~14周歲 C.1周歲 D.10~12周歲
A.突觸 B.反射弧 C.傳入神經(jīng)纖維 D.傳出神經(jīng)纖維
A.平滑肌和骨骼肌 B.骨骼肌和心肌 C.心肌和平滑肌 D.以上都不正確