题目

根据短文理解完成下列各题。C Tom is a junior high student. He is good at some subjects but his favourite subject is chemistry. Yesterday he met some trouble when he had his chemistry class. At that moment, Tom was doing an experiment in class. He tried twenty times, but he couldn't succeed. So he decided to stop doing the experiment. He felt really unhappy. His teacher came up to him and asked why he was unhappy. Tom said, All my work is in vain (白费力气). I fail twenty times and I get nothing. Tom's teacher touched Tom's head with a smile. He said to Tom, Oh, you do a lot and研究温度对凝乳酶催化乳汁凝固的影响。先将酶和乳汁分别放入两支试管，然后将两支试管放入同一水浴（温度用T0C表示）中持续15min，再将酶和乳汁倒入同一试管中混合，保温并记录凝乳所需要的时间。通过多次实验，并记录不同温度下凝乳所需要的时间，结果如下表：关于该实验的下列叙述正确的是              （      ） 装置 A B C D E F 水浴温度（T0C） 10 20 30 40 50 60 凝乳时间（min） 不凝固 7.0 4.0 1.5 4.0 不凝固 A、该实验说明酶的活性受温度的影响  B、凝乳酶的最适温度肯定是400C C、将A内混合物加温到400C不会发生凝乳   D、将F内混合物冷却到400C会发生凝乳