问题
单项选择题
代号为R717的制冷剂分子式是（）。
A、CO2
B、NH3
C、H2O
答案
参考答案：B
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代号为R717的制冷剂分子式是（）。
A、CO2
B、NH3
C、H2O
参考答案：B
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| Two Americans from England were 1 in Spain. One morning they came 2 a little restaurant for lunch.They did not know the native(当地的) 3 and their waiter did not know 4 ,either. They wanted their waiter to 5 that they asked 6 some milk and bread.At last they read the word "milk" many times. They spelled it. But the waiter could not understand them. At last one of them took a piece of paper and began 7 a cow.When he was just finishing 8 it,the waiter looked at it and ran out of the restaurant. "Do you 9 ?"said the American," 10 clever I am!"After some time,the waiter retured to the restaurant. He brought no milk or bread with him,mstead,he brought a bull-fighting(斗牛) in front of him. | ||||
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