问题
选择题
常温时,将的氨水滴加到
的盐酸中,下述结论中正确的是( )
A.若混合溶液的pH=7,则
B.若,
,则混合液中
C.若混合液的pH=7,则混合液中
D.若,且混合液的pH<7,则一定有
答案
A
强酸与弱碱反应,如果恰好完全反应,溶液呈酸性;如果溶液呈中性,则碱溶液过量.
常温时,将的氨水滴加到
的盐酸中,下述结论中正确的是( )
A.若混合溶液的pH=7,则
B.若,
,则混合液中
C.若混合液的pH=7,则混合液中
D.若,且混合液的pH<7,则一定有
A
强酸与弱碱反应,如果恰好完全反应,溶液呈酸性;如果溶液呈中性,则碱溶液过量.
The Japanese Macaca monkey has been studied in the wild for over 50 years. In 1952, on one small Japanese island, scientists dropped some 26 in the dirt for the monkeys. The monkeys liked their taste, but they found the dirt 27 . One clever 18-month-old monkey found she could 28 the problem by washing the sweet potatoes in a nearby river. She taught this to her mother. Her 29 also learned this new way and they taught their mothers, too. All the younger monkeys 30 learned to wash the dirty sweet potatoes to make them 31 to eat. But many old monkeys found it very hard to learn this and still ate the 32 sweet potatoes. Then something very surprising 33 . In the autumn of 1958, scientists found that the monkeys on other nearby 34 began washing their sweet potatoes too. Scientists still don’t fully understand how this knowledge was 35 from one island to another.
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