Water causes the wood fibers to expand, making the "V" open up and causing the coin to drop into the cup.

水会使木纤维膨胀，让V型扩展开来，硬币因此掉进杯中。

youdao

Water causes the wood fibers to expand, making the "V" open up and causing the coin to drop into the cup.

水会使木纤维膨胀，让V型扩展开来，硬币因此掉进杯中。

youdao