题目内容
【题目】【2016届河北省保定市高三期末调研】阅读下面材料，在空白处填入适当的内容（1个单词）或括号内单词的正确形式。
Polar bears live in such environment that is too cold for most animals. For much of the year, they live and hunt on the 【1】 (freeze) Arctic sea ice. Nature has prepared them for the cold conditions but nothing has prepared them for the danger 【2】 threatens(威胁) their only home.
The polar bears’ world is melting. Polar bears 【3】 (suffer) in a warmer world are in danger. Studies show that the polar ice 【4】 (reduce) by 9.8% every 10 years since 1978.At present , about 20,000 to 25,000 polar bears live in the Arctic. Polar bears depend on the sea ice for their 【5】 (survive). “The sea ice is more than just the platform that the bears walk 【6】 ,” says Andrew Derocher, who studies North American polar bear populations. “Without 【7】 , they can’t exist.”
Some melting and refreezing of the polar ice is natural. But in a 【8】 (warm) world, these cycles speed up, and bears have less time to hunt. 【9】 (normal), they have three months in the spring when they gain more weight and the extra fat is used later, 【10】 the bears are not actively hunting. Therefore, it is urgent to protect the environment and maintain the ecological balance.
【答案】
【1】frozen
【2】that/which
【3】suffering
【4】has reduced
【5】survival
【6】on
【7】it
【8】warmer
【9】Normally
【10】when
【解析】
试题分析：通过本文考查学生的词性在语境中的正确运用能力。包括动词的时态，非谓语动词，副词，代词，连词等。
【1】frozen 考查形容词。这里用形容词修饰名词, frozen 冰冻的。
【2】that/which 考查定语从句关系词。这里the danger是先行词，在定语从句中作主语，所以用关系代词that/which。
【3】suffering 考查非谓语动词。suffering in a warmer world是非谓语动词短语做后置定语修饰Polar bears，Polar bears是suffer的逻辑主语，所以用动词的-ing形式suffering。
【4】has reduced 考查谓语动词的时态。since 1978提示是现在完成时，the polar ice相当于it和reduce自己是主谓关系，所以是has reduced。
【5】survival 考查名词。用名词作介词宾语for their，所以用名词形式survival。
【6】on 考查介词。the platform 和不及物动词walk之间加on才能构成介词和宾语的关系。
【7】it 考查代词。it指the polar ice，意思是：没有极地冰，北极熊就不能存在。
【8】warmer 考查形容词比较级。极地冰由于变暖而融化，冷了在结冰，但是比较暖和的世界里，这样的循环就会加速。
【9】Normally考查副词。这里用副词修饰全句，句意：正常情况下，他们在春天有3个月，变胖增加脂肪以备后用。
【10】when 考查非限制性定语从句的关系词。句意：脂肪在北极熊不能积极主动去打猎的时候用。
