He is systematically advancing his work.

I work at a travel agency.

That traveller is travelling around the world.

He likes to take a walk in the park at dusk.

Linear programming is a part of operations research and is used to find the optimal solution.

Please remember to bring your travel documents.

The students on a field trip visited the museum.

Paying the urban planning tax is a citizen's duty.

The United Nations Environment Programme is providing solutions to global environmental problems.

We should always remember the power of Kannon in difficult times.