Объяснение
Step 1: read the whole sentence: after running I'm very …, I want a big glass of water. The blank follows “很”, so it is an adjective. Step 2: the pinyin “kě” (third tone) fits two HSK 3 characters: “可” (as in 可以) and “渴” (thirsty). The clause “想喝一大杯水” (want to drink water) shows it must be “渴”. Step 3: how to write it: the water radical “氵” on the left – thirst needs water – and “曷” on the right. Common mistake: writing “喝” (hē, to drink), which has the same right-hand part but the mouth radical “口” instead of “氵”.