题目内容：

阅读下面材料，在空白处填入1个适当的单词或括号内单词的正确形式。

Agricultural experts say crop diversity is important to feed the1.(increase) population of our planet. They say having a large variety of plants also2.(help) to protect against possible crop diseases and future crises. But many experts say the number has decreased sharply during the past century.

One of the world's 3.(large) seed conservation projects has predicted further losses. The Millennium Seed Bank Partnership is warning that up to one hundred thousand plant species could 4. (permanent) disappear. The rich collection of genes5. decide their qualities would disappear with them.

Many experts blame climate change and loss of habitat, normal growth area, for damaging plant life. They say human6.(activity) and poorly planned, overly heavy use of land also are responsible. Modern business farming is responsible7.loss of farmers' traditional crop varieties. The "Green Revolution" of the twentieth century changed agriculture. Some experts say the use of modern commercial farming methods saved millions of people from8.(starve). Farmers planted, watered, and fertilized their crops with the help of machines. They treated their fields with chemicals9.(control) diseases and insects. Harvests grew larger and higher quality,10. another result was that some traditional crops were lost. Damage to the environment over the past century makes people believe that crop diversity also suffered.