架设两套完全相同的（如图甲）加热装置，两套装置的试管中分别装有少量的相等体积的M固体和N固体.它们的加热时间﹣﹣温度曲线如图乙所示（M为实线，N为虚线），在35min内M物质从固体熔化成了液体，N物质始终是固体。则下列说法正确的是（　　）

根据短文理解，从A、B、C、D四个选项中选择最佳答案填空。

    One day, a farmer took a bag of wheat to town. He didn't know what 1 when the bag fell off his horse. The bag was 2 heavy for him to lift. He hoped that 3 would come and help him.

    Before long a man came over. But the farmer was 4 when he saw the man, because he was the famous judge(法官) in "town. The farmer was afraid to ask him for 5.

    As soon as he came up to the farmer, the judge 6 his horse and said," You need my help, don't you? Let me help you." Then he took one end of the bag, and the farmer took 7. They 8 the bag of wheat onto the horse.

    "Sir," asked the farmer, "how can I 9 you?"

    "Well," the judge replied, " 10 you see anyone in need of help, do the same for him."

刘明：2.54，2.48，2.50，2.48，2.54，2.52

张晓：2.50，2.42，2.52，2.56，2.48，2.58

近视眼可以通过配戴近视镜加以矫正．近视镜是（   ）