I attended a lecture on economics today.

The Yangtze River is the longest river in China.

He began to feel the symptoms of a cold.

A blush rose on her cheeks from embarrassment.

She blushed out of embarrassment.

I saw some bad signs from his complexion.

A public hearing is an important place to listen to the opinions of citizens.

Jellyfish have a coelenteron.

In ancient times, small countries used to send tributes to the great powers.

Every year, they paid tribute to the king.