These days, however, goose bumps are 18 to human beings.
答案：(B) no longer useful
語意「雞皮疙瘩對人類來說已經『不再有用』」，no longer useful 符合，呼應前文說這個反應是祖先體毛較多時期演化來的，現在人類體毛已經很少了；even more ridiculous（更荒謬）、still quite convenient（仍然很方便，語意相反）、more than important（不通順）都不合。
本題大考中心未公布逐題答對率，以下不談數據，只談觀念。
四個選項都是「形容詞片語」形式的補語，如果沒讀出 however 帶出的轉折方向，很容易挑到正面的那兩個。
四個選項都是補語，可見這一格考的是語意，關鍵在 however。前一句是 Back in the days when our ancestors may have had a lot more body hair, this might have helped to keep them warm or scare an oncoming predator.（在我們的祖先體毛多得多的年代，這或許有助於保暖或嚇退逼近的掠食者。）——講的是過去有用。本句是 These days, however, goose bumps are ___ to human beings.（然而如今，雞皮疙瘩對人類來說……。）These days 與 Back in the days 對照、however 標示轉折，所以要說的是「現在沒用了」，填 no longer useful。再用常識驗算：現代人體毛稀少，豎起那點毛既保不了暖，也嚇不走任何東西。
still quite convenient（仍然相當方便）、more than important（不只是重要）：兩個都是正面的，與 however 的轉折方向相反。even more ridiculous（更加可笑）：帶著評價的口吻，而這一段是在客觀說明生理反應的演化，不是在嘲笑它。
no longer（不再）、be useful to sb（對某人有用）、these days（如今）、back in the days（在過去那個年代）、an oncoming predator（逼近的掠食者）、keep sb warm（讓某人保暖）。
Goose bumps are one of those fight-or-flight reactions of the sympathetic nervous system. When you experience cold or fear, a nerve reaction is sent to the muscles, which then contract involuntarily. This muscle contraction causes your body hair to stand erect. The skin with standing body hair 16 a goose's skin after its feathers have been plucked—hence the name goose bumps. But 17 is this helpful to us as a response to fear or cold?
Back in the days when our ancestors may have had a lot more body hair, this might have helped to keep them warm or scare an oncoming predator. These days, however, goose bumps are 18 to human beings.
Goose bumps, or the reflex that causes them, also occur in many other mammals. Many mammals fluff up their fur when 19 , to look bigger and thus more dangerous. For example, when a porcupine encounters a predator, its long sharp pointed hairs will stand up as a means of 20 . In animals with a thick hair coat, the rising of hair traps more air between the hairs, providing another layer of insulation to keep them warm.