Chen volunteered to lead the literacy program at the community center.

I didn't catch his name, so on the sign-up sheet I wrote Chen as a placeholder.

The Chens arrived early to set up the reunion decorations.

Chen's theorem offers a powerful partial result toward the Goldbach conjecture by showing that every sufficiently large even number can be expressed as the sum of either two primes or a prime and a semiprime.

The mathematician explained how a Chen prime can be used in sieve methods to estimate gaps between primes.

Graduate students often study Chen primes when exploring generalizations of twin primes.

Traders docked in Chen-chiang to load jars of soy sauce and ceramic wares bound for southern markets.

During the summer, tourists often take day trips to Chen Pao to see the nesting sea turtles.

Ching-te-chen's craftsmen perfected techniques that made its porcelain prized across the world.

Historians still debate the territorial status of Chen Pao Island after the 1969 skirmishes.