The oldest and most common ...

【專家解說】：【答案】
【小題1】C
【小題2】A
【小題3】C
【小題4】B
【答案解析】文章大意：本文是一篇科技說明文。文章介紹了biomass(生物量)的特征、生物量的優(yōu)點以及它在美國能源中的地位。
【小題1】細(xì)節(jié)理解題。根據(jù)第二段中的“because the energy it contains comes from the sun.When plant matter is burned, it gives off the sun's energy.In this way, biomass serves as a sort of natural battery for storing the sun's energy.”可知C正確。
【小題2】推理判斷題。根據(jù)第三段中的“In 2008—although the numbers aren't all in yet—wind power probably took over first place because of the rapid development of wind farms across the country.”可知，2008年風(fēng)能占居首位。關(guān)鍵詞定位：A項中的the leader of 和first place為同意表達(dá)。
【小題3】推理判斷題。根據(jù)最后一段中的“Some homeowners also try to make their own heat by using biomass materials.Such practice may save homeowners' money, but it also produces a lot of pollution.So, the best way is to encourage power plants to use it.”可知C正確。
【小題4】推理判斷題。根據(jù)全文內(nèi)容可知，本文是一篇有關(guān)生物量能源的科普類文章。所以，它應(yīng)該是科學(xué)雜志上的文章。故選B。