Once upon a time, there was a poor fisherman in a village near the sea .He always dreamed of having a lo t of money. One day ,he heard that a big ship with a lot of gold sunk in the nearby water.Because of this , for a long time he often went to the sea and hoped to find the gold .

      One day, he was sitting on his boat daydreaming, he suddenly(突然) felt something heavy pulling(拉)on his fishing rod (钓竿).He thought that good luck had come to him , and he pulled hard at it . "Wow! A big, gold chain(金链子)!" He said happily when he saw the thing He then began to pull at the gold chain to try to get it all into the boat, but there seemed to be no end to it. When he got the more gold chain , the more water came into his boat .

       But, the fisherman did not know it .He began to dream of a big house , a big piece of land , buying horses and cows…… He kept pulling in the chain though the boat kept sinking. At last ,the boat went under the sea and the fisherman died (死)

回答下列与实验相关的问题：

（1）“探充pH对酶活性影响”的实验中，向试管中添加（①淀粉②酸或碱③淀粉酶）这三种物质的正确顺序是　____ （填数字），理由是____

（2）据专家推测塑化剂有可能使儿童性早熟，为了探究塑化剂是否会导致儿童性早熟，某生物兴趣小组利用小白鼠做实验进行相关探究．（材料用具：略）

实验步骤：

①取生长发育状况等相同的成年雌性小白鼠3只分成三组，并编号为A、B、C；

②A组小白鼠用一定量饲料饲养，B组小白鼠用等量的拌有塑化剂溶液的饲料饲养，C组小白鼠用等量的拌有雌激素的饲料饲养；

③在相同适宜环境中饲养一段时间后，观察并记录各组小鼠的性成熟的快慢．

请分析回答：

a．该实验方案在步骤①有两处不妥，请纠正____ ；．

b．如果按更正后的实验进行，预测结果应是：若____ ，则说明塑化剂会使小鼠性早熟；若　____ ，则说明塑化剂不会使小鼠性早熟．

读一读，选出发音不同的一项。