如图是甲乙两种固体物质（均不含结晶水）的溶解度曲线，请你根据曲线回答一下问题．

（1）50℃时，60g的甲物质加入到100g水中充分溶解，最终形成溶液的质量为____ g．

（2）30℃时，甲的饱和溶液比乙的饱和溶液溶质质量分数____（填“大”、“小”或“相等”）．

（3）50℃时，等质量的甲、乙饱和溶液降温到20℃，析出晶体多的是____（填“甲”或“乙”）．

唐朝时期出现的新的生产工具是（    ）

含有抗生素的牛奶不能发酵成酸奶，原因是（　　）

根据短文内容，选择正确答案。
A
    One day, Mr. and Mrs. White went shopping by car. They stopped their car near a store. They bought a lot of things and they wanted to put them in their car. But Mr. White couldn't open the door of the car. “Let's ask a policeman for help.” said Mrs. White. They asked a policeman to help them. The policeman was very friendly to help them open the door of the car. Just then a man came up and shouted, “What are you doing with my car?” Mr. and Mrs. White took a look at the number of the car. It was not their car.

关于神经细胞动作电位的叙述，错误的是（  ）