回答有关人体内环境自稳态调控问题．

人较长时间静止站立，脑供血量减少，形成一过性晕厥．下列是长时间站立引起的血压变化及其调节机制（见图1）．

（1）下肢静脉储血量增加而引起血压降低，主要原因是心脏射血量____ 所导致．

（2）低压刺激后，经神经、激素调控后，引起系统变化，使血压恢复正常水平，其中A、B的变化分别是____ 、____ ．

（3）低压也可由过程⑦的调节，引起肾脏对水分重吸收功能增强，出现肾排尿量降低的现象，则参与该调节过程的激素是____ ．

（4）如果心脏射血量不变，血液粘滞度增加，主要增加____ （填收缩压或舒张压）．

人体的血压经常因为环境因素与自身活动状况的改变而发生相应变化，同时通过人体的一系列调节机制保持相对稳定．图2是健康中年人一天24小时的血压变化情况．

（5）在6点起床后，人体的血压出现“晨起高峰”的现象，这主要与____ 神经突然兴奋，继而____ 两类激素分泌增加有关；其次，还可能与夜间饮水少，导致____ 增大有关．

（6）比较、分析24小时的收缩压与舒张压的变化特点：

变化的主要共性特征：____ ．

变化的主要差异是：收缩压的绝对变化量大于舒张压的绝对变化量这是因为____ ．

自秦朝历汉唐至明清两千多年间，中国古代国家的主要特征是（    ）

①皇帝“家天下”制度  ②中央集权制度  ③“多民族”与“大一统”  ④分裂

    In Thailand, people do not eat with chopsticks, like in China, Japan, and Korea. They use spoons and forks.____Because most food is already cut. If you need to cut things use the side of your spoon.____ If you are right-handed, keep the spoon in your right hand and the fork in your left hand.

    ____ The rice is not on the same plate with the other food. It is not necessary to finish all you rice or all your food. It is good to leave a little on your plate. If you eat anything, it means you want more.

    ____The host(主人)will ask you two or three times if you want more food . It is the same with whatever you are drinking. During the meal, never empty your cup or glass. When it is less than half full, your host or neighbor will fill it again.____ Always refill(再加满) your neighbor's glass. This means that you must keep an eye on your neighbor's glass all through the meal.