请回答下列问题：

（1）﹣定温度下，向0.1mol/LCH₃COOH溶液中加入少量CH₃COONa晶体时，下列说法正确的是____ ．（填代号）

a．溶液的pH减小 b．CH₃COOH的电离程度减小

c．溶液的导电能力增强  d．溶液中c（OH^﹣）•c（H⁺）不变

（2 ）25°C 时，0.10mol/L Na₂CO₃ 溶液的 pH=11，则溶液中由水电离出的 c（OH^﹣）=____ mol/L．

（3）己知快K_sp只与温度有关，溶解平衡：CaCO₃（s）⇌Ca²⁺+（aq）+A^2﹣（aq）△H＞0．

①温度升高时，K_sp____．（填“增大”“减小”或“不变”，下同）

②向浊液中通入HCl气体c（ Ca²⁺）____ 

（4）己知醋酸的电离常数k=1.8×l0⁵．25°C时，向CH₃COOH溶液中加入一定量的NaHCO₃，所得混合液的 pH=6，则混合液中 c（CH₃COO^﹣）/c（CH₃COOH）=____ ．

    Once there was an island where all the feelings lived: Happiness, Sadness, Knowledge, and all of the others, including Love. One day it was said that the island would go down, so all made boats and left except Love.
Love was the only one who stayed. Love wanted to offer her help until the last possible moment. When the island had almost gone down, Love decided to ask for help.
      Richness was passing by Love in a great boat. Love said, “Richness, can you take me with you?” Richness answered, “No, I can't. There is a lot of gold and silver in my boat. There is no place here for you.”
       Sadness was close by, so Love asked, “Sadness, let me go with you .” “Oh, Love, I am so sad that I need to be by myself!”
Happiness passed by Love, too, but she was so happy that she did not even notice when Love called her.
Suddenly, there was a voice, “Come, Love, I will take you.” It was an elder. Love was so excited that she even forgot to ask who the elder was. So Love asked Knowledge, another elder, “Who helped me?” “It was Time,” Knowledge answered. “Time?” asked Love. “But why did Time help me?”
      Knowledge smiled with deep wisdom and answered, “Because only Time understands how valuable Love is.”