针对运动损伤的疼痛常用“冷疗法”治疗，其原理是用一种叫做氯乙烷的气态有机物，对准损伤处喷射，使人体受伤部位的温度降低，皮肤血管收缩，神经纤维传导速度变慢，防止伤口处形成淤血，同时减缓人的伤痛感．氯乙烷采用 ____的方法液化后储存在罐中，喷在皮肤上迅速 ____（填物态变化名称），同时 ____大量的热．

    It's Sunday. Children don't go to school on Sundays. But Kate gets up early in the morning. “It's my birthday. I'm eight years old today.” she thinks, “Where are Dad and Mum? I want to know what they can give me for my birthday.”

    Her father and mother are not at home. They are going shopping. And now they are talking about what to buy for Kate.

—Dad: How about the doll? It looks nice. I think Kate would like the doll.

—Mom: I don't think so. She is not a little girl. I think she likes a new dress. Girls often like new dresses very much.

—Dad: But she has a few new dresses and some new blouses. Oh, I think she must be very happy to have a box of colorful pencils and some picture books. Do you think so?

— Mom: Yes. Let's go over there and buy them.

现有盐酸和CaCl₂的混合溶液，向其中逐滴加入过量的某物质X，溶液的pH随滴入X的量的变化关系如图所示，则X可能是（　　）

敲击鼓面，在听到鼓声时，还可看见鼓面上小纸团在跳动，说明鼓声是由于鼓面的____ 产生的；鼓面的____ 越大，鼓声的响度越大．