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Egyptians

Mesopotamians

1处连字符,2处破折号

The Egyptians, the Mesopotamians, American Indians and the Chinese developed advanced systems of agriculture. They knew the value of fertilization, irrigation, and drainage, and they developed improved varieties of plants and animals by choosing the best ones. Advances were made in 18th-century England where horse-drawn farming machines, improved systems of crop rotation and fertilization, and better breeds of sheep and cattle were developed. Meanwhile, Europeans were exploring the New World. They returned home with crops previously unknown in Europe – white and sweet potatoes, corn, pumpkins, and tomatoes. One plant, the potato, was found to grow well in cold, damp climates and on poor soils. It soon became an important food item in northern Europe. In the 20th century the major advances were in three areas – chemistry, breeding, and technology. Modern farming depends heavily on chemical fertilizers and insect control. Other chemicals control plant diseases and weeds.