一列说法正确的是（ ）
A．向一定温度下的饱和溶液中添加溶质后其溶质质量分数增大
B．饱和溶液降温析出晶体后的溶液仍为饱和溶液
C．从50g10%的硫酸钠溶液中取出5g，这5g溶液中硫酸钠的质量分数为1%
D．在一定温度下，物质X和Y具有相同溶解度，则在该温度下X、Y的饱和溶液中含X、Y两种物质的质量相等
A、饱和溶液中添加该种溶质不会再溶解，故A错误；
B、析出晶体后的溶液一定是饱和溶液，故B正确；
C、由于溶液是均一的，从50g10%的硫酸钠溶液中取出5g，这5g溶液中硫酸钠的质量分数仍为10%，故C错误；
D、则在该温度下X、Y的饱和溶液中溶质质量分数相等，但溶质不一定相等，因为溶液质量不知道，故D错误．
故选B．
Jill and Jenny were the best of friends. They were_ so much of the time that people said that they were like twins. They did _ __ and went everywhere together. One day, however, something that_ __ caused their friendship to break happened. Jill had already made plans with Jenny to watch a(n) _ _ . At the last minute, Jill’s mother had an errand （差事）to run and Jill__ __ look after her sister. Jenny was disappointed(失望的) but said that she would still_ _ Jill and watch the show together. The next morning, Jill overheard Jenny telling another friend,“I watched it last night. It was a wonderful show.” Jill got _ _ .She walked past Jenny and gave her a cold look. Jenny __ _why Jill was so angry with her. When Jenny called out to Jill, she ignored(不理) her. After school, Jenny waited for Jill, __ __, for their walk home together. However, Jill just_ __ on alone. Jenny ran after her and asked,“What’s the matter, Jill? Why are you avoiding __ __ like this?” Jill answered angrily,“You broke your _ _ . A good friend should not do that.” Jenny realised what the _ _ was and laughed. “I didn’t go to the show. I just watched another show on TV. I will _ _ break my promise to you. You are my best friend.” Jill said _ _ to Jenny and they were the best friends again.
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