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地面、海洋、湖面、植物表面、土壤里的水分,每时每刻都在挥发,变成水蒸气,进入大气层.含有水蒸汽的湿空气,由于某种原因向上升起.在上升过程中,由于周围空气越来越稀薄,气压越来越低,上升空气体积就要膨胀.膨胀的时候要消耗自身的热量,因此,上升空气的温度要降低.温度降低了,容纳水汽的本领越来越小,上升空气里的水汽很快达到饱和状态,温度再降低,多余的水蒸气就附在空气里悬浮的凝结核上,成为小水滴.如果温度比0℃低,多余的水蒸气就变成为冰晶.它们集中在一起,受上升气流的支托,飘浮在空中,成为我们能见到的云.

全国各地多次采用人工降雨的方法解决旱情.

人工降雨的方法多种多样,有高射炮、火箭、气球播撤催化剂法、有飞机播撒催化剂法.其中飞机播撒催化剂法就是用飞机在厚度比较大的云雾中播散干冰(固态二氧化碳)和催化剂(碘化银),从而达到降雨目的.干冰的作用是当干冰变成气体时,使周围的温度急剧下降,空气中的水蒸气就附在空气里悬浮的凝结核(碘化银)上,成为小水滴,或者有些水蒸气就变成成为冰晶.冰晶增大到一定程度就会下落,下落过程中遇到暖气流变成水,跟原来的水混在一起,便产生了降雨.

请指出题目中相关语句属于哪种物态变化和个别物态变化的吸放热情况:

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   I’m lying on my back in my grandfather’s orchard (果园), looking up at the branches above me. It is one of the last days of summer. Already the days are shorter and the nights are cooler. Some kinds of apples are already ripe(成熟的). Others will be ready to pick soon. I think of my grandmother’s apple pie, and how I used to make it with her. She died last year, before the apple harvest, and I have not had her pie since then. I really miss her. I hear bees busily humming about, visiting the late summer flowers. The gentle hum of their wings nearly sends me to sleep.
   The sky is as blue as my grandfather’s eyes. Above me, big white clouds ran across the sky like pieces of cotton blowing in the wind. School starts in another week, and time seems to have slowed down.
   “Sophie!” calls my grandfather. “Is that you?” I stand up, take his hand, and tell him all about my day as we walk through the orchard. We talk about apples, and bees and Grandma. He tells me that he misses her too.
   He hputs his rough, brown farmer’s hand around my shoulder and pulls me close. “ You know, Sophie,” he says, “ I spent the morning in the attic (阁楼), and you’ll never guess what I found. It’s the recipe(烹饪法) for Grandma’s apple pie. I used to help her make it sometimes. I can’t do it all alone, but you used to help her too. Maybe between the two of us, we can work it out. Want to try?”
   “ But it won’t be the same without Grandma,” I tell him.
   “ That’s true,” he says, “but nothing is the same without Grandma. Still, I don’t think that she would want us never to have another apple pie. What do you say?” I nod yes, and we walk towards home…toward an afternoon in the farmhouse kitchen, making Grandma’s famous apple pie.