Ever since they were first put on the market in the early 1990s, genetically modified (GM, 转基因) foods have been increasingly developed and marketed in many countries in the world, mainly on the basis of their promise to end the worldwide food crisis. But can GM technology solve world hunger problems? Even if it would, is it the best solution?
Despite what it promises, GM technology actually has not increased the production potential of any crop. In fact, studies show that the most widely grown GM crop, GM soybeans, has suffered reduced productivity. For instance, a report that analysed nearly two decades of research on major GM food crops shows that GM engineering has failed to significantly increase US crop production.
Something else, however, has been on the rise, While GM seeds are expensive, GM companies tell farmers that they will make good profits by saving money on pesticides（杀虫剂）. On the contrary, US government data show that GM crops in the US have produced an overall increase in pesticide use compared to traditional crops. “The promise was that you could use less chemicals and boost production. But neither is true,” said Bill Christison, President of the US National Farm Coalition.
At the same time, the authors of the book World Hunger: Twelve Myths argue that there actually is more than enough food in the world and that the hunger crisis is not caused by production, but by problems in food distribution and politics. These indeed deserve our efforts and money. Meanwhile, the rise in food prices results from the increased use of crops for fuel rather than food, according to a 2008 World Bank report.
As a matter of fact, scientists see better ways to feed the world. Another World Bank report concluded that GM crops have little to offer to the challenges of worldwide poverty and hunger, because better ways out are available, among which “green” farming is supposed to be the first choice.
The author develops the second paragraph mainly      .

A．by classification	B．by comparison
C．by example	D．by process

What does the underlined word “boost” in the third paragraph probably mean?

A．Control.

B．Evaluate

C．Obtain.

D．Increase.

GM companies promise farmers that they will benefit from ______________.

A．practicing “green” farming

B．use of less chemicals

C．fair distribution of their crops

D．using more crops for fuel

Which of the following best describes the attitude of the author towards GM technology?

A．Optimistic

B．Defensive

C．Disapproving

D．Casual