6. The farmers had the tractors____24 hours during the harvest season. A. working B. work C. worked D. Dto work ...

35: It is true that the US now has a "free market" system. A: 错误 B: 正确 ...

40: According to the US Constitution, Congress exercises the legislative power. It enjoys the power of making laws, levying taxes and appropriating money for government expenditure. A: 错误 B: 正确 ...

30: The continental USA runs 4505 kilometers from its Atlantic coast to Pacific coast，and 2574 kilometers from Canada to Mexico. A: 错误 B: 正确 ...

25: The first computer came into being in 1944and in the same year, the first atom bomb was tested. A: 错误 B: 正确 ...

17: The largest seaport of the United States is (). A: San Diego B: San Francisco C: Chicago D: New York ...

37: Before the breakout of the Civil War, the Whig Party, which had been formed during Jackson's day, began to break up. A: 错误 B: 正确 ...

31: In 1965, the USA launched the world's first communication space satellite —"Early Bird" A: 错误 B: 正确 ...

23: The successful merchants and ship-builders became the forefathers of the American bourgeoisie in industry. A: 错误 B: 正确 ...

16. The Washington Post was founded in 1876 and associated with the conventional conservative force in the Congress. A. 错误 B. 正确 ...