In the 1970s, many people became concerned about energy. People in developed countries had to face up to the fact that they used too much energy, and energy sources weren"t going to last forever. One architect, Michael Reynolds, decided to do something about this. He set out to design homes that were cheaper to build and more energy-efficient. In addition, he wanted to do something about the rubbish problem, and came up with the idea of "earthships".

填空题 The main material used to build an earthship is 1 filled with dirt.

填空题 After both the inside and outside walls are built, they are then 1 to make the house look like an ordinary house.

填空题 In earthships, 1, which is collected on the roof, is used for drinking and bathing.

填空题 In the last paragraph, the phrase which means "have become popular and fashionable" is 1.

单选题 Read the question and the four choices marked A, B, C and D, and decide which is the best choice according to the passage.
What is the main idea of this passage?

A、 Environmentalists are concerned about energy.
B、 Earthships have been built in many different countries.
C、 Earthships look like typical houses.
D、 Earthships are environmentally friendly homes.

【正确答案】 D

【答案解析】[解析] 该篇文章主要围绕earthships而展开，首先描述了earthships兴起的原因，接着对其建造和益处进行了描述，并且最后一段对以上内容进行总结，指出“环保是earthships流行开来的原因之一”，因此选项D最能概括本篇文章的内容。