(20—23題為題組) 
(B) One of the world’s sourest liquids has been used in cooking, as medicine, and forcleaning purpose. It has even been mixed with sugar water to create a refreshing drink. Whatexactly is this multi-purpose ingredient? It’s none other than vinegar. __20 __in almostevery kitchen in the world, vinegar was accidentally discovered one day in ancient times justlike wine, __21__ comes from grape juice left undisturbed. __22__ , wine left untouchedtransforms into vinegar due to further fermentation of the existing sugars in the originalgrape juice. Nowadays, vinegar can be made from a wide __23__ of products, includingapples, sugar cane, coconuts, honey, and even rice.
【題組】20.
(A) To find
(B) Finding
(C) Found
(D) Been found )