问题
单项选择题
精馏塔投用前，要先启动塔顶冷凝器的目的是（）。
A、防止超压
B、防止塔底蒸干
C、防止塔的升温速度超标
D、防止气相物料从塔顶排出，减少物料的排放损失
答案
参考答案：A
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精馏塔投用前，要先启动塔顶冷凝器的目的是（）。
A、防止超压
B、防止塔底蒸干
C、防止塔的升温速度超标
D、防止气相物料从塔顶排出，减少物料的排放损失
参考答案：A
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| The boy in the picture is my new friend. 1 name is Jack. He is 2 the U.K. Now he lives in Shanghai with his mother. He is thirteen years old. He has 3 black hair, just like me. There is always (总是) a smile (微笑) on his 4 and we all love him. He is 1.76 metres tall but he doesn't 5 playing basketball. He loves table tennis, 6 Zhang Jike is his favourite player. He 7 near our school, so (所以) he often plays table tennis in the gym after school. Jack likes Chinese 8 very much. His mother often takes him to the Chinese restaurants on weekends. 9 are his favourite. He wants to 10 Beijing."Beijing is a beautiful and great city!" he says.  | ||||
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