He couldn't pronounce the word correctly.

His Japanese pronunciation is very natural.

Predicting the occurrence of earthquakes is difficult.

When the earthquake occurred, we evacuated immediately.

This region has seen remarkable economic development in recent years.

His dog started to go into heat yesterday.

His dog has entered the mating season.

This gem luminesces under special conditions.

The gem emits light in the darkness.

The joy of drawing a green dragon in mahjong is exceptional.