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问题 解答题
2005
1
2
-2004
1
3
+2003
1
2
-2002
1
3
+2001
1
2
-2000
1
3
+…+3
1
2
-2
1
3
+1
1
2
-
1
3
．
答案

原式=（2005+

1
2
）-（2004+
1
3
）+（2003+
1
2
）-（2002+
1
3
）+…+（1+
1
2
）-
1
3

=[+++…+（3-2）+1]+（

1
2
-
1
3
）×
2006
2

=1×

2006
2
+
1
6
×1003

=

7021
6
．

问答题

室温下，有下列四种溶液，根据题目要求填空（溶液体积变化忽略不计）

①②③④
溶液氨水氢氧化钠溶液醋酸盐酸
pH111133
（1）在①中加入氯化铵固体，溶液的pH变化是：______（填增大、减小或不变）．

（2）分别将等体积的③和④加水稀释100倍，所得溶液的pH：③______④（填＞、=或＜）．（3）②、③两溶液混合，若所得溶液的pH=7，则c（CH3COO一）______c（Na+）（填＞、=或＜）．

（4）①、④两溶液等体积混合，所得溶液呈______性（填“酸”、“碱”或“中”）．
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单项选择题

"I would almost rather see you dead. " Bobert S. Cassatt, a leading banker of Philadelphia, shouted when his twenty-year-old eldest daughter announced that she wanted to become an artist. In the 19th century, playing at drawing or painting on dishes was all right for a young lady, but serious work in art was not. And when the young lady’ s family racked among the best of Philadelphia’s social families, such an idea could not even be considered.
That was how Mary Cassatt, born 1844, began her struggle as an artist. She did not tremble before her father’s anger, she opposed him with courage and at last made him change his mind. Mary Cassatt gave up her social position and all thoughts of a thousand and a family, which in those times was unthinkable for a young lady. In the end, after long years of hard work and perseverance, she became America’s most important woman artist and the internationally recognized leading woman painter of the time.

What do we know about Robert Cassatt’s character from the text

A. He was a cruel man.
B. He was a stubborn (固执的) man.
C. He knew nothing about art.
D. He knew little about his daughter.
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