This old radio uses a pentode.

The arctic tern is known for its long-distance flights.

The Arctic Tern, also known as 極鯵刺, can be seen in the Arctic region.

This diode only allows current to flow in one direction.

He is a master of Bajiquan.

The circumpolar star is always visible in the north.

He thought he was smart, but he remembered the proverb 'a fool may give a wise man council', and understood the importance of listening to others' opinions.

He was deeply thinking about '稽'.