In addition, the leftover material following the removal of fibers can even be used as a natural fertilizer back in the pineapple fields. 25 its low cost, this innovative material is already being used by many leading fashion companies to make their products.
答案：(A) Due to
語意「由於成本低廉，這個創新材料已經被許多知名時尚公司採用」，Due to（由於）符合這個因果邏輯；Nothing but（只不過）、In contrast to（與……相反）、On behalf of（代表）都不合。
表示原因你最先想到的一定是 because，但 because 後面要接完整子句，例如 Because it is cheap, ...。這一格空格後面是 its low cost，一個沒有動詞的名詞片語，所以要找的是幾個字合起來當一個介系詞用的那一型，不是連接詞——連接詞後面接的是子句。劍橋 English Grammar Today 的 Prepositions 條目就是這樣處理的：some pairs and groups of words operate like single prepositions，它列出的例子有 because of、in place of、in addition to、in front of、up to。先把這一步分清楚，選項馬上就篩掉一半。
能接名詞又表示原因的就是 Due to。整句是 Due to its low cost, this innovative material is already being used by many leading fashion companies（由於成本低廉，這個創新材料已經被許多知名時尚公司採用），前因後果順著走。用國中熟悉的說法對照一次：Due to its low cost 等於 Because of its low cost（後面接名詞），也等於 Because it is cheap（後面接子句）。同樣接名詞表原因的還有 owing to（由於）、on account of（由於），在正式寫作裡大致可以互換。順帶一提，早期有些用法書主張 due to 只能放在 be 動詞後面，例如 The delay was due to rain.，不宜放句首；但這個限制現在已被主要辭典與用法書視為過時的講究，這裡放句首完全站得住。
Nothing but（只不過是、只有）用來強調「除了……什麼都不是」，不表原因。In contrast to（與……相反、對比之下）表對比，但成本低和被採用之間是因果不是對比。On behalf of（代表……）用於代表某人出面做事，和句意無關。這個「原因 vs 讓步」的辨析是克漏字反覆出現的考點：109 年第 29 格就要你在 owing to（由於）和 in spite of（儘管）之間做選擇，兩題可以一起記。
due to（由於，接名詞）、owing to（由於，接名詞）、because of（因為，接名詞）、on account of（由於，接名詞）、because + 子句（因為……）、nothing but（只不過是）、in contrast to／with（與……相反）、on behalf of（代表……）、leading companies（龍頭企業、知名企業）。
The pineapple, a delicious tropical fruit, has been valued for centuries not only for its distinct and unique taste, but also for its miraculous health and medical benefits. But pineapples can also be a fashionable fruit: Pineapple leaves can 21 a substitute for leather.
The idea was developed when a Spanish designer travelling to the Philippines observed a traditional Filipino shirt 22 together with the fibers of pineapple leaves. After five years of research, she created from pineapple leaves a material which, like real leather, can be used for making bags, shoes, and 23 textile products. It is an eco-friendly and biodegradable fiber.
This eco-friendly leather has clear 24 for the environment, compared to real leather and synthetic leathers. It requires fewer chemicals, making it safer for the workers in factories. Its manufacture also leaves a smaller carbon footprint. In addition, the leftover material following the removal of fibers can even be used as a natural fertilizer back in the pineapple fields. 25 its low cost, this innovative material is already being used by many leading fashion companies to make their products.