
pH 计的校正方法是将电极插入一标准缓冲溶液中,调好温度值。将斜率旋钮调到最大,调节定位旋钮至仪器显示 pH 值与标准缓冲溶液相同。取出冲洗电极后,在插入另一标准缓冲溶液中, ( ) 不动,调节 ( ) 至仪器显示 pH 值与标准缓冲溶液相同。此时,仪器校正完成,可以测量。但测量时,定位旋钮和斜率旋钮不能再动。
A. 定位旋钮、斜率旋钮 B. 斜率旋钮、定位旋钮 C. 斜率旋钮、斜率旋钮 D. 定位旋钮、定位旋钮


A. 定位旋钮、斜率旋钮 B. 斜率旋钮、定位旋钮 C. 斜率旋钮、斜率旋钮 D. 定位旋钮、定位旋钮
The Bedouin people, a tribe living in the deserts of Arabia and Northern African, think most highly of people who show loyalty. To them loyalty does not mean that one is devoted to a country, a place, or a leader. Loyalty means being faithful to one’s family and tribe.
The Bedouin people are proud of their ancestors(祖先). They do not admire a hero from an ordinary or poor family as much as one who comes from an honored family. They especially respect those who have inherited(继承) a good family name and then have passed it on to their children.
A man’s position among his people depends upon his ancestors, relatives, and fellow tribesmen. If they are honored, he is also honored. If they are disagreed, he, too, is disgraced. Therefore, one carefully guards the honor of his family and his tribe.
A man can protect his family’s honors by being brave and generous and by giving protection to those who ask for it. He also guards it by carefully watching the women of his family.
A Bedouin woman cannot bring honor to her family, but she can bring disgrace. Even if a woman only looks as if she has done something wrong, she may be killed. The honor of her family depends upon her virtue(美德).