The agricultural revolution in the nineteenth century involved two things the invention of labor-saving machinery and the development of scientific agriculture. labor-saving machinery naturally appeared first where labor was scarce. "In Europe", said Thomas Jefferson, "the object is to make the most of their land, labor being abundant; here it is to make the most of our labor, lard being abundant". It was in America, there fore, that the great advances in nineteenth-century agricultural machinery first Came. At the opening of the century, with the exception of a crude plow, farmers could have carried practically all of the existing agricultural implements on their backs: by 1860, most of the machinery in use today had been designed in an early form. The most important of the early inventions was the iron plow. As early as 1990 Charles Newbold of New Jersey had been working on the idea of a cast-iron plow and spent his entire fortune in introducing his invention. The farmers, however, would home none of it, claiming that the iron poisoned the soil and made the weeds grow. Nevertheless many people devoted their attention to the plow, until in 1869, James Oliver of South Bend, Indiana, turned out the first chilled-steel plow.
　　
　　
16. The word "here" (para 1,line 4) refers to _____.
[A] Europe
[B] America
[C] New Jersey
[D] Indiana

17. Which of the following statements is NOT TRUE?
[A] The reed for labor helped the invention of machinery in America.
[B] The farmer rejected Charles Newbold's plow for fear of ruin of their field.
[C] Both Euorpe and America had great need of farm machinery.
[D] It was in Indiana that the first chilled-steel plow was produced.

18. The passage is mainly about _____.
[A] the agricultural revolution
[B] the invention of labor-saving machinery
[C] the development of scientific agriculture
[D] the farming machinery in America

19. At the opening of the nineteenth-century,farmers in America _____.
[A] preferred light tools
[B] were extremely self-reliant
[C] had many portable tools
[D] had very few tools

20. Implied but not stated _____.
[A] There was a shortage of workers on American farms.
[B] The most important of the early inventions was the iron plow.
[C] After 1869,many people devoted their attention to the plow.
[D] Charles Newbolt had made a furtune by his cast-iron plow