Over80percentofmankind’sdietisprovidedbytheseedsofles...
问题详情:
Over 80 percent of mankind’s diet is provided by the seeds of less than a dozen plant species. But the amount and variety of crop production has been increasing all the time.
____56____For example, Egyptians settled along the River Nile, the Chinese empire along the Yellow River, and the Mesopotamian countries along the Tigris and Euphrates rivers. The river systems provided these early civilizations with a consistent source of silt(泥沙)from the yearly floods and water for the crops. 57
Farming changed very little from early times until about 1700. In the 1700s an agricultural revolution took place, which led to a large increase in the production of crops. 58 These crops, such as corn and potatoes, produced very large yields.
In the 1850s, the industrial revolution came to the farm with new mechanized methods. 59 Early on, the biggest changes were in the use of new farm tools. 60 The new tools, combined with crop rotation(轮作), manure(粪肥)and better soil preparation, led to a steady increase in crop yields in Europe. Later on, the arrival of steam power and, later, gasoline-powered engines represented a big step forward in the production of crops.
A. These methods greatly increased production rates.
B. So people had to work out a new plan to manage the water
C. Many of the early civilizations began along major river systems.
D. Most of the early tools were still powered by horses, oxen or men.
E. Silt is like a natural fertilizer, bringing new minerals to enrich the soil
F. How to increase the crop production has been a problem for human beings
G. One great change in this revolution was the adoption of some different crops
【回答】
CEGAD
知识点:七选五题型
题型:未分类
-
用若干个体积为1的正方体搭成一个几何体,其正视图、侧视图都是如图所示的图形,则这个几何体的最大体积与最小体积的...
问题详情:用若干个体积为1的正方体搭成一个几何体,其正视图、侧视图都是如图所示的图形,则这个几何体的最大体积与最小体积的差是()A.2B.3C.4D.5【回答】解析:由正视图、侧视图可知,此几何体的体积最小时,底层有5个小正方体,上面有2个小正方体,共7个小正方体;体积最大时,底...
-
_______________,听取蛙声一片。 (*弃疾《西*月•夜行黄沙道中》)
问题详情:_______________,听取蛙声一片。 (*弃疾《西*月•夜行黄沙道中》)【回答】稻花香里说丰年知识点:其他题型:填空题...
-
下列物质中,属于合成材料的是 A.棉花 ...
问题详情:下列物质中,属于合成材料的是 A.棉花 B.羊毛 C.塑料 D.天然橡胶【回答】C知识点:走进化学世界单元测试题型:选择题...
-
我国的汽车工业正在飞速发展,一辆现代轿车,从动力到小小的天线都与物理学有关,某国产新型轿车,在平直公路上行驶时...
问题详情:我国的汽车工业正在飞速发展,一辆现代轿车,从动力到小小的天线都与物理学有关,某国产新型轿车,在平直公路上行驶时,当车速为36km/h时,制动后滑行距离为10m。则轿车所受的制动阻力大小是其轿车重力大小的倍数为(g=10m/s2) A.0.10 B.0...
相关文章
- 任务型阅读Doyouneedusefulandinterestingbooks?Herewe'vegotple...
- Toextinguish(熄灭)differentkindsoffires,severaltypesoffir...
- People 61(live)indifferentcountriesmadedifferentkindsof...
- Ifoverweightpeopleeatlessandtakemoreexercise,they’llso...
- 完形填空。IthinkI’vealwaysbeeninterestedinfood.Mygrandparent...
- TakeActionforaBetterWorld:VolunteersNeededSixmonths’pre...
- ---Thestudentslookverytiredafterthesportsmeeting.---We...
- ExploreandDiscover:ACityTourDiscoversomeofWinnipeg’shis...
- Inagreatmanycities,hundredsofpeopleridebikestoworkevery...
- LastweekendIvisitedRomeforthefirsttime.Ispentthreebusyd...