荸荠
Chinese water chestnut; Eleocharis dulcis or E. congesta
毕其功于一役
to accomplish the whole task at one stroke (idiom)
避其锐气,击其惰归
avoid the enemy when he is fresh and strike him when he is tired and withdraws (idiom)
怀璧其罪
lit. treasuring a jade ring becomes a crime (idiom); to get into trouble on account of a cherished item; fig. A person's talent will arouse the envy of others.