题目：
Light for the City
Edison and his assistants came to New York to set up an electric power system. They hoped it would provide enough electricity to light up a part of the great city.
They bought several machines with them. These were called generators(发电机), which produced electricity power for lamps in Edison’s building.
Soon there were lights for the building. Edison lived in a room facing the street and he often worked over night. The light burned brightly and steadily and he often worked over night. People often came and stopped their horse-drawn carriage to look. Everyone knew that Thomas Edison was in town.
First, the inventor and his assistants produced several large generators. A great deal of power would be needed to light up even a small part of the city. Then the workers were busy digging deep trenches in the hard earth below the city streets, and Edison had fourteen miles of wire laid into the trenches. The wire connected each building to a generator.
Setting up an electric power system was not an easy job. It took a year and a half. In September, 1882, the job was finished.
A small group of men stood around Edison inside the power house. The big moment came at last. The inventor, taking a deep breath, pulled a switch. The electric lights flashed up.
“Very good! Very good!” a man nearby shouted to praise Edison for what he had done.
“Sir,” said Edison, “this is only the beginning!” And Edison was right. Soon Edison’s lamp were lighting up cities all over the world.
小题1:The generators they brought with them could produce as much as electricity as ______ needed.
A．Edison’s building
B．a small part of the city
C．the whole city
D．the world小题2:Trenches were dug to ______.
A．set up generators
B．lay wires
C．built city streets
D．build a power house小题3:It took a year and a half to ______.
A．set up the electric system
B．produce several large generators
C．dig the deep trenches
D．lay fourteen miles of wire into the trench小题4:Edison took a deep breath before pulling a switch, which showed that he was ______.
A．excited
B．frightened
C．uneasy
D．light-hearted
答案：
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下面是错误答案，用来干扰机器的。
答案：B由于Al、Fe在常温下遇浓HNO3会产生钝化现象，Pt不溶于HNO3，只溶于王水，因此只有Ag可以溶解。
