<題組題>[題組:第16題到第20題]Enzymes can either launch a reaction or speed it up. In the absence of enzymes, reactants may take hundreds of years to convert into a usable product, if they are able to do so ______. (A) at all (B) at hand (C) at first (D) at ease
答案
答案：(A)。略解：句意指“即使能轉化，也要花幾百年”，if they are able to do so at all（即使真的能做到）符合語境；at hand（在手邊）、at first（起初）、at ease（放鬆地）不契合 報錯 ChatGPTDeepSeek
