神经、肌肉、腺体受阈刺激产生反应的共同表现是（）
A.收缩
B.分泌
C.局部电位
D.阈电位
E.动作电位
参考答案：E
—What made your skin look so terrible?
—______ to the sunlight for a long time．[ ]
A. Because it was exposed
B. After being exposed
C. Being exposed
D. Exposed
声门噪声能量
