问题
选择题
下列各组离子能大量共存于同一溶液中，且加入过量NaOH溶液或少许稀硫酸时，都能产生白色沉淀的是 [ ]
A．Ba2＋、Mg2＋、NO3－、CO32－
B．Na＋、Al3＋、Cl－、AlO2－
C．Ba2＋、K＋、Cl－、HCO3－
D．NH4+、Fe3＋、Ba2＋、Cl－
答案
答案：C
搜题请搜索小程序“爱下问搜题”
下列各组离子能大量共存于同一溶液中，且加入过量NaOH溶液或少许稀硫酸时，都能产生白色沉淀的是 [ ]
A．Ba2＋、Mg2＋、NO3－、CO32－
B．Na＋、Al3＋、Cl－、AlO2－
C．Ba2＋、K＋、Cl－、HCO3－
D．NH4+、Fe3＋、Ba2＋、Cl－
答案：C
| 完型填空。 | ||||
| I once had a teacher whose husband died suddenly of heart attack. About a week after his death, she 1 some of her thoughts with a classroom of students. As the late afternoon sunlight shone 2 the classroom windows, and when the class was nearly over, she 3 a few things aside on the edge of her desk and sat down. With a 4 look on her face, she paused and said, " 5 class in over, I'd like to share with all of you a deep 6 which I feel is very important. Each of us is put here on 7 to learn, share, love, appreciate and give of ourselves. 8 of us knows when this fantastic experience will 9 . It can be taken away at any moment. Perhaps this is the God's 10 of telling us that we must make the 11 of every single day." Her eyes were beginning to 12 , but she went on, "So I would like you all to make me a 13 : From now on, on your way to school, or on your way home, find something beautiful to 14 . It doesn't have to be something you see. It could be a 15 of freshly baked bread floating out of someone's house, or it could be the sound of the soft 16 rustling (使发出沙沙声) the leaves in the trees…Please look for these things, and 17 them, for at anytime they can all be taken away…" The class was completely 18 . We all picked up our books and went out of the room silently. That 19 , I observed many more beautiful things on my way home from school than usual. Remember: Life is not 20 by the number of breaths we take, but by the moments that take our breath away. | ||||
|