题目

哺乳动物的生殖活动与光照周期有着密切联系。下图表示光暗信号通过视网膜→松果体途径对雄性动物生殖的调控过程。请回答相关问题：（1）在光暗信号调节的反射弧中，效应器是__________。在此反射弧中，神经纤维的某部位由兴奋状态恢复为静息状态时，膜内的电位变化为__________。（2）松果体细胞的作用是将__________转变为激素信号，从而将神经调节与体液调节紧密联系起来。褪黑素由松果体细胞产生，能对身体不同部位的靶器官如下丘脑、垂体--I________ you ________ in New York. How long have you been in America? --Oh, a week. [　　] A, don't know; were B. haven't known; are C. hadn't known; were D. didn't know; were