Agricultural experts say crop diversity is important to feed the【1】(increase) population of our planet. They say having a large variety of plants also【2】(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 genes【5】 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 human【6】(activity) and poorly planned, overly heavy use of land also are responsible. Modern business farming is responsible【7】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 from【8】(starve). Farmers planted, watered, and fertilized their crops with the help of machines. They treated their fields with chemicals【9】(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.

【答案】

【1】increasing

【2】helps

【3】largest

【4】permanently

【5】that/which

【6】activities

【7】for

【8】starvation

【9】to control

【10】but/while/yet

【解析】

这是一篇说明文。农作物的多样性对养活地球上不断增长的人口很重要。但是有很多植物正在消失，原因是气候变化和（这些植物）栖息地的丧失。

【1】考查现在分词。句意：农作物的多样性对养活地球上不断增长的人口很重要。根据句意，这里要表达的是“增长的”。increase的现在分词形式increasing可以用做形容词修饰名词 ，意为“增加的”符合句意，故填increasing。

【2】考查时态。分析句子成分可知help在宾语从句中做谓语，主语是having a large variety of plants ，是单数，所以谓语动词要用单数。全文时态为一般现在时，所以这里也要用一般现在时，故填helps。

【3】考查形容词的最高级。句意：世界上最大的种子保护项目之一预测将会有更多的损失。根据句意，这里要用所给形容词的最高级，故填largest。

【4】考查副词。所给词用来修饰动词disappear, permanent为形容词不能用于修饰动词，所以要用其副词形式permanently，故填permanently。

【5】考查定语从句。分析句子成分可知为___5___ decide their qualities that/which 定语从句，先行词为genes，为物。空格处引导定语从句且在从句中做主语，先行词为物，要用that/which来引导这个定语从句，故填that/which。

【6】考查名词单复数。activity为可数名词，本句中没有冠词，说明要用其复数形式，故填activities 。

【7】考查固定搭配。be responsible for 为固定搭配，意为“对……负责”，所以这里要填介词for。

【8】考查名词。句意：一些专家说现代商业农业方法的使用使数百万人免于饥饿。空格处为介词from的宾语，starve为动词，不能做宾语，所以用其名词形式starvation。故填starvation。

【9】考查不定式。句意：他们用化学药品来防治疾病和昆虫。根据句意，(control) diseases and insects. 是treated their fields with chemicals的目的，所以用不定式表目的，填to control。

【10】考查连词。句意：收成越来越多，质量也越来越好，另一个结果是一些传统作物消失了。根据句意，Harvests grew larger and higher quality与was that some traditional crops were lost.之间是转折关系，一个是好处，一个是坏处，所以要用表示转折关系的连词连接前后两个句子，故填 but/while/yet。

语法填空题型经常考查动词的使用。在所给词为动词时，考生先判断动词在句中做非谓语还是谓语，如果分析句子成分后发现所给动词在从句中做谓语，要考虑动词的时态，语态和单复数。比如第2小题分析句子成分可知help在宾语从句中做谓语。help的主语是having a large variety of plants ，是单数，所以谓语动词要用单数。全文时态为一般现在时，所以这里也要用一般现在时，综合填 helps。