Multiple choice general knowledge Big as a biscuit, deep as a cup, Even a river can't fill it up. What is it? A sponge Carpet A kitchen strainer A mirror Reveal answer Fill a bubble to check yourself C Correct answer Explanation A kitchen strainer fits the riddle perfectly - it's cup-like in shape but full of holes, so water passes right through it instead of filling it up. Sponges absorb water, carpets soak it up, and mirrors don't hold liquid at all.