题目

阅读理解Nov. 21 is World Hello Day. It began back in the 1970s as part of an effort to make the world more peaceful. It was created by the United Nations just after the war between Israel and Egypt in 1973. The philosophy (理念) behind it is: Say “Hello” and stop war.It sounds like a fine idea, but most of us know that simply saying “Hello” won't bring about world peace. Still, on a smaller range, the simple act of saying hello to someone can make a lot of difference.This might not be obvious. After all, it's such a casual thing and requires so little effort. You raise your head 3．人体内激素分泌量过多或不足都会对机体有害，体内有一系列机制维持激素在血液中含量的相对稳定．如图表示下丘脑神经分泌细胞、垂体细胞、甲状腺细胞及它们分泌的激素之间的关系．请据图回答：（1）当身体的温度感受器受到寒冷刺激时，相应的神经冲动传到下丘脑．引起下丘脑分泌的激素A是促甲状腺激素释放激素（TSH）．由此可知，这种生理过程是由神经和体液（激素）共同调节的．（2）寒冷环境中C激素在血液中的含量上升，作用于骨胳肌和其他组织后，能加速细胞中有机物的氧化放能，从而增加产热量．（3）正常体温，如果激素C的合成量过多时，图中激素A、B含量将下降，这是一种（负）反馈调节机制．（4）感冒发烧时应多喝水，此时血浆渗透压降低，刺激下丘脑中的渗透压感受器，垂体释放的抗利尿激素减少，使肾小管、集合管对水分的重吸收减弱，尿液增加，有利于毒素排出体外．