下列与化学反应能量变化相关的叙述正确的是（）。
A．生成物总能量一定低于反应物总能量
B．放热反应的反应速率总是大于吸热反应的反应速率
C．应用盖斯定律，可计算某些难以直接测量的反应焓变
D．同温同压下，
在光照和点燃条件下的△H不同
参考答案：C
解析：
A项，吸热反应中生成物总能量大于反应物总能量，放热反应中生成物总能量小于反应物总能量；B项，化学反应速率与该反应是放热反应还是吸热反应没有关系；C项，反应的焓变只与反应的始态和终态有关，与反应过程和途径无关；D项，同一反应焓变相同。
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| Wings of Angel I used to hate myself because I wasn't "normal". Everyone else could play on the monkey bars and ride on a bicycle, but not 1 . I had a severe spinal cord disorder (脊髓病) and I knew l would always be much 2 than others. I hated going to school and hated people 3 at me. I hated seeing others smiling broadly and standing 4 and tall. And most of all, I hated looking in the 5 and seeing an ugly hunchback (驼背). My friends found me 6 because I didn't let others get close to me. I thought I was going to go on like this for the rest of my life 7 Angela appeared. That afternoon, I was sitting by myself in a corner of the school-a spot where no one would 8 me. That's when I first heard her voice. "Hi. Can I sit down?" I raised my head and there she was, with an irresistible smile on her round face. "What are you looking at?" she asked. "Ants." "What are they doing?" "No 9 ." "I bet they're playing games and Making friends. Don't you think so?" That was how our 10 started and it didn't stop. We talked about everything under the sun-the ants, the clouds, my little niche (处境)-until it was sunset. Then suddenly, she saw my 11 . She just stared. My heart 12 . What I feared most had happened and I knew for sure she would 13 me now. She stood up, pointed at my back and said, "I know 14 your back is hunched." I closed my eyes like a crimiml waiting to be 15 . I begged in my heart for her to 16 , but she just kept on going. "I know what you've got in there. Do you?" "No," I answered 17 . She bent and whispered in my ears. "Your back is hunched because you've got a pair of wings from the angels." I was 18 . I looked into her eyes and her 19 touched my heart. From that day on, I started to leam to 20 myself because I have the wings of an angel and a kind-hearted friend. | ||||
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