时空穿梭

• 日(sun; day)RADICAL
• 寸(inch; unit of measurement)PHONETIC

Time flows like the sun moving inch by inch across the sky.

• 穴(row; gap)RADICAL
• 工(craftsman; work)PHONETIC

An empty cave with nothing inside is just hollow space.

• 穴(hole; gap)RADICAL
• 牙(tooth)PHONO-SEMANTIC

Use your teeth to bite through a cave or hole – that's how to remember the character for piercing through.