Question

We experience different forms of the Sun’s energy every day. We can see its light  and feel its warmth. The Sun is the major source of evaporation (蒸发) of water from the oceans and lakes. Sunlight also provides the energy used by green plants to make their own food. These green plants then provide food for all organisms (生物) on the Earth.

Much of the energy that comes from the Sun never reaches the Earth’s surface. It is either reflected or absorbed by the gases in the upper atmosphere. Of the energy that reaches the lower atmosphere, 30% is reflected by clouds or the Earth’s surface. The remaining 70% warms the surface of the planet, causes water to evaporate, and provides energy for the water cycle and weather. Only a tiny part, approximately 0.023%, is actually used by green plants to produce food.

Many gases found in the atmosphere actually reflect heat energy escaping from the Earth’s surface back to the Earth. These gases act like the glass of a greenhouse in that they allow energy from the Sun to enter but prevent energy from leaving. They are therefore called greenhouse gases.

When sunlight strikes an object, some of the energy is absorbed and some is reflected. The amount reflected depends on the surface. For example, you’ve probably noticed how bright snow is when sunlight falls on it. Snow reflects most of the energy from the Sun, so it contributes to the low temperatures of winter. Dark-coloured surfaces, such as dark soil or forest, absorb more energy and help warm the surrounding air.

1.According to the passage, the root cause for weather changes on the Earth is ______.

A．the atmosphere surrounding the Earth	B．water from oceans and lakes
C．energy from the Sun	D．greenhouse gases in the sky

2.Only a small part of the Sun’s energy reaches the Earth’s surface because most of it _______________.

A．absorbed by the clouds in the lower atmosphere

B．reflected by the gases in the upper atmosphere

C．lost in the upper and lower atmosphere

D．used to evaporate water from the oceans and lakes

3.We learn from the passage that _______________.

A．all living things on the Earth depend on the Sun for their food

B．a forest looks dark in winter because it absorbs solar energy

C．only 0.023% of the energy from the Sun is made use of on the Earth

D．greenhouse gases allow heat energy to escape from the Earth’s surface

Answer

1.C

2.C

3.A

【解析】

科普文，讲述有关太阳能的问题。

1.考查学生的查寻具体信息的能力，细读全文可知，地球上天气变化的根源在于太阳能。

2.考查细节理解能力，从文章第二段首句可知，太阳能只有小部分才能到达地表，大多被表层大气所反射或吸收。A、B两项表述过于片面，且与文意不符，只有B项才概括全面。其中lose一词用的恰到好处，可以涵盖reflect和absorb之意。

3.考查学生的推理判断能力，从文章第一段末句可知，地球上所有生物均要依靠太阳能来间接为他们提供食物。B 、C、 D 三项表述皆与文意相违。