题目内容

Farmers can increase their corn crops three times simply _________ watering their fields．

A.
through
B.
with
C.
by
D.
in

C
by doing…表示方式，“通过做……”。

练习册系列答案

暑假作业与生活陕西师范大学出版总社有限公司系列答案

暑假作业人民教育出版社系列答案

暑假作业上海科学技术出版社系列答案

暑假作业内蒙古教育出版社系列答案

暑假最佳学习方案假期总动员白山出版社系列答案

暑假大串联系列答案

相关题目

If you want to stay young, sit down and have a good think. This is the research finding of a team of Japanese doctors, who say that most of out brains are not getting enough exercise, and as a result, we are growing old unnecessarily soon.
Professor Taiju Matsuzawa wanted to find out why quite healthy farmers in northern Japan appeared to be losing their ability to think and reason at a rather early age, and how the speed of getting old could be slowed down.
With a team of researchers at Tokyo National University, he set about measuring brain sizes of a thousand people of different ages with different jobs.
Computer technology helped the researchers to get most exact measurements of the sizes of the front and side parts of the brain, which have something to do with thinking and feeling, and decide the human character. As we all know, the back part of the brain, which controls task like eating and breathing, does not contract(萎缩) with age.
Contraction of front and side parts, as cells(细胞) die off, was seen in some people in their thirties, but it was still not found in some sixty and seventy-year-olds.
Matsuzawa concluded from his tests that there is a simple way to prevent the contraction---using the head.
The findings show that contraction of the brain begins sooner in people in the country than those in the towns. Those with least possibility, says Matsuzawa, are lawyers, followed by university professors and doctors. White-collar workers doing the same work day after day in government offices are, however, as possible to have contracting brains as the farm workers, bus drivers and shop assistants.
【小题1】 The team of doctors wanted to find out ____.