问题
单项选择题
根据YDT5077—2005《固定电话交换设备安装工程验收规范》,程控交换设备的标称直流工作电压为-48v,直流电压允许变化范围()。
A.为-57v~-40v
B.为-50v~-47v
C.为-60v~-40v
D.为-57v~-30v
答案
参考答案:A
根据YDT5077—2005《固定电话交换设备安装工程验收规范》,程控交换设备的标称直流工作电压为-48v,直流电压允许变化范围()。
A.为-57v~-40v
B.为-50v~-47v
C.为-60v~-40v
D.为-57v~-30v
参考答案:A
A young man was getting ready to graduate(毕业)from college. For many months he had admired(欣赏,羡慕) a beautiful sports car in a seller's showroom, and knowing his father could it, he told him that was all he wanted. On the morning of his graduation day his father called him into his own study and told him how he was to have such a fine son. He handed his son a beautiful gift box. but slightly(轻微地) disappointed, the young man opened the box and found a lovely book. ,he raised his voice at his father and said, "With all your money you only give me a book?" Then he rushed out of the house, the book in the study. He didn't contact(联系) his father for a whole year one day he saw an old man who looked like his father in the street. He realized he had to go back home and see his father. When he arrived at his father's house, he was told his father had been in hospital for a week. When he was going to the hospital, he saw the new book still on the desk, just as he had left it one before. He opened it and began to turn the pages. Suddenly, a car key _____ from an envelope(信封) behind the book. It had a tag(标签).On the tag was the of his graduation, and the words PAID IN FULL.
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