题目

The story begins with fishing. Once a boy and his father went fishing before bass (a kind of special fish) season opened. They were fishing early in the evening, catching other fish with worms. Then the boy tied on a small silver lure (鱼饵) and put it into the lake. Suddenly he felt that something very big pulling on the lure. His father watched with admiration as the boy skillfully brought the fish beside the bank. Finally he lifted the tired fish from the water. It was the largest one he had ever seen, but it was a bass(the special fish). The boy and his father looked at the big 如图所示是某晶体的温度随加热时间变化的图象．由图可知这种晶体的熔点是    ℃，图中与横轴平行的BC段表示这种晶体处于    过程．（填物态变化）