The orange is on desk and the desk is in his room.[ ]
A. the, the
B. the, a
C. the, /
答案:C
在烧杯A中装入20mL蒸馏水,滴入2~3滴石蕊试液;在烧杯中B中装入10mL浓盐酸,然后用一只大烧杯把A、B两烧杯溶液罩在一起(如图).过几分钟后,可以观察到烧杯A中液体变成__________色.由该实验可知(浓)盐酸具有的性质是:
(1)________________________;
(2)________________________.
简述“相对性原理”。