This comparative advantage is 27 by key factors of production such as land, capital, and labor.
答案：(D) determined
【句型】be determined by 字詞搭配「由……決定」；installed（安裝）、reserved（保留）、opposed（反對）都不合。
determined 你背的多半是形容詞「堅決的、下定決心的」（a determined look，堅定的神情），所以看到 is determined by，腦中翻成「有決心」就講不通，只好放棄。這個「形容詞印象蓋掉動詞本義」的落差，正是本題答對率只有 48% 的主因。determine 當及物動詞的核心意思是「決定、左右」，被動 be determined by 就是「由……決定」。
先看句子結構：This comparative advantage（這種比較利益）+ is + 空格 + by + key factors of production such as land, capital, and labor（土地、資本、勞力等關鍵生產要素）。被動語態的 by 帶出的是動作的執行者，所以空格填的動詞，必須能讓「生產要素」對「比較利益」做點什麼。土地、資本、勞力能對比較利益做什麼？只能是「決定它」。還原成主動句驗算最保險：Key factors of production such as land, capital, and labor determine this comparative advantage.（土地、資本、勞力等關鍵生產要素決定了這種比較利益。）把 install、reserve、oppose 分別代進這個主動句，馬上就會發現不通。前一句也在鋪路：A country is said to have a comparative advantage over another when it can produce a commodity more cheaply.（一國若能以更低的成本生產某項商品，就說它對另一國擁有比較利益。）成本由什麼構成？就是土地、資本、勞力 — 前後兩句正是「什麼是比較利益」接上「比較利益由什麼決定」。
installed（安裝）裝的是設備或軟體，抽象的「比較利益」不能被安裝。reserved（保留；預訂）例 reserve a table（訂位），當形容詞時是「拘謹的、保守的」。opposed（反對）後面固定接 to，be opposed to war（反對戰爭），介系詞就對不上這裡的 by。
be determined by（由……決定）、determine（決定；查明）、determined（堅決的、下定決心的）、be opposed to（反對）、install software（安裝軟體）、reserve a table（訂位）、factors of production（生產要素）、such as（例如）。
International trade is the exchange of goods and services between countries. Trade is driven by different production costs in different countries, making 26 cheaper for some countries to import goods rather than make them. A country is said to have a comparative advantage over another when it can produce a commodity more cheaply. This comparative advantage is 27 by key factors of production such as land, capital, and labor.
While international trade has long been conducted in history, its economic, social, and political importance has been 28 in recent centuries. During the 1990s, international trade grew by nearly 8.6 each year. In the year 1990 alone, the growth in trade in services was as high as 19. Today, all countries are involved in, and to varying degrees dependent on, trade with other countries.
29 international trade, nations would be limited to the goods and services produced within their own borders. Trade is certainly a main 30 force for globalization. It is also the subject of many international agreements that aim to govern and facilitate international trade, such as those negotiated through the World Trade Organization (WTO).