Today the earth is getting warmer and warmer. But hundreds of years a    1    , people had a different problem—a 400-year cold period! From the 1400s to the 1800s, winters in the northern half of the earth were c    2     and longer than they are now. Scientists c    3     this time the “Little Ice Age” (小冰期).

The colder weather b    4     many serious problems. Plants died of cold and illness spread among people. People had to spend a lot more time collecting wood for fires to keep their house warm. And sometimes, a h    5     piece of ice would slide down (滑落) a mountain and destroy (摧毁) some villages.

Scientists think the Little Ice Age was caused by forces (力量) that people could not control. One cause (起因), in their opinion, was the sun. The sun often has “storms” of energy called sunspots (太阳黑子). During the Little Ice Age, there were fewer sunspots than there are t    6    . With fewer sunspots, the sun was giving out less e    7     which made the earth warm. Volcanic eruption (火山爆发) was probably a    8     natural cause. During the Little Ice Age, many volcanoes erupted. Their dust (灰尘) might stop the sun’s l    9     and heat from reaching the earth.

Today we are seeing the influences of rising temperature. Scientists think people are causing this change by b    10     a lot of coal and oil. So we need to change our way of living.

1.1.

A

B

C

D

解析：选ago。根据前文 “Today the earth is getting warmer”（如今地球越来越暖）和转折词 “But”，可知此处对比的是 “几百年前” 的情况。首字母为 a，“hundreds of years ago” 是固定搭配，意为 “几百年前”，符合语境。

2.2.

A

B

C

D

解析：选colder。后文有比较级标志词 “than”，结合小冰期的背景，此处应描述冬季 “更寒冷”。首字母为 c，形容词 cold 的比较级是 colder，契合 “比现在更冷、更漫长” 的语义。

3.3.

A

B

C

D

解析：选call。此处缺少谓语动词，结合句意 “科学家将这段时期____为‘小冰期’”，“call sth. sth.” 是固定搭配，意为 “把某物称为某物”。主语 Scientists 是复数，且文章整体为一般现在时，故填动词原形 call。

4.4.

A

B

C

D

解析：选brought。空格后接 “many serious problems”（诸多严重问题），首字母为 b，动词 bring 有 “带来” 之意。文章描述小冰期的过去情况，需用一般过去时，bring 的过去式是 brought。

5.5.

A

B

C

D

解析：选huge。修饰名词短语 “piece of ice”（冰块），需填形容词。结合 “滑落摧毁村庄” 的语境，可知冰块体积大，首字母为 h，huge 意为 “巨大的”，符合逻辑。

6.6.

A

B

C

D

解析：选today。前文对比小冰期和当下的太阳黑子数量，此处 “than there are” 后需接时间状语。首字母为 t，“there are” 用一般现在时，对应现在的时间，故填 today（如今）。

7.7.

A

B

C

D

解析：选energy。太阳黑子减少会导致太阳释放的某种物质减少，而这种物质能让地球变暖。首字母为 e，energy 意为 “能量”，“give out energy” 表示 “释放能量”，符合太阳提供热量的科学常识。

8.8.

A

B

C

D

解析：选another。前文已提及太阳活动这一个自然原因，此处介绍火山爆发，应为 “另一个” 自然原因。首字母为 a，another 修饰单数可数名词，表 “三者及以上中的另一个”，契合语境。

9.9.

A

B

C

D

解析：选light。火山灰会阻挡太阳的某种物质和热量到达地球，首字母为 l，light 意为 “光”，“sun’s light and heat” 表示 “太阳光和热”，符合火山灰遮挡阳光的科学原理。

10.10.

A

B

C

D

解析：选burning。结合常识，燃烧煤炭和石油会导致气温上升，首字母为 b，动词 burn 意为 “燃烧”。空格前有介词 by，后接动词 - ing 形式，故填 burning。