I am learning how to solve differential equations.

Solving a linear equation is difficult.

Understanding chemical equations is difficult.

The new law has been publicly announced.

The city has publicly announced a new plan.

He cited the delay of the train as an excuse for being late.

He always prepares his favorite bait before going fishing.

My name is Kankaiji.

That workman is working hard.

I think his marriage is really an auspicious event.