Liǎng kuài mùbǎn pīn de yánsī héfèng.
The two boards fit together perfectly with no gaps.
Tā de zhèngcí yánsī héfèng, zhǎo bú dào pòzhàn.
His testimony was airtight — no holes to be found.
Zhège jìhuà zhíxíng de yánsī héfèng.
The plan was executed flawlessly.
