Its traditional 27 is based on forestry, animal husbandry and subsistence agriculture.
答案：(D) economy
traditional economy（傳統經濟）呼應後文 these account for less than 50% of the GDP now（如今這些僅占國內生產毛額(GDP)不到一半），表示不丹過往的傳統經濟型態以林業、畜牧業與自給農業為基礎；culture／politics／religion 均不符合後文 GDP 的總體經濟學語境。
四個選項都是抽象名詞、都能接在 traditional 後面，你會憑印象挑一個；culture 尤其眼熟，因為整篇最後就在講傳統文化。
答對率不到五成，鑑別度高達 63，是本批最會分人的題目之一，分開的是有沒有先看空格後面列的那三樣東西。空格後是 based on forestry, animal husbandry and subsistence agriculture（以林業、畜牧業與自給農業為基礎）——三樣都是產業，是一個國家靠什麼生產與謀生的部分，那就是 economy（經濟）。填進去讀成 Its traditional economy is based on forestry, animal husbandry and subsistence agriculture。下一句用 GDP 這個經濟指標講「如今這些只占國內生產毛額不到一半」，再一次確認。
culture（文化）在整篇最後一段確實出現過（傳統藏傳佛教文化），形態也吻合，容易被順手選走，但文化不會「以林業與畜牧業為基礎」；politics（政治）與 religion（宗教）同理，三種產業撐不起政治或宗教。
be based on（以……為基礎）、forestry（林業）、animal husbandry（畜牧業）、subsistence agriculture（自給農業）、GDP（國內生產毛額）、landlocked（內陸的、不臨海的）。
The Kingdom of Bhutan is a landlocked nation situated between India and China. The entire country is mountainous, 26 a small strip of subtropical plains in the extreme south. The elevation gain from the subtropical plains to the glacier-covered Himalayan heights exceeds 7,000 m.
Its traditional 27 is based on forestry, animal husbandry and subsistence agriculture. However, these 28 less than 50 of the GDP now that Bhutan has become an exporter of hydroelectricity. Besides, cash crops and tourism are also 29.
Bhutan is one of the most isolated nations in the world, 30 foreign influences and tourism regulated by the government to preserve its traditional Tibetan Buddhist culture. It is often described as the last surviving refuge of traditional Himalayan Buddhist culture.