Ayaka is my best friend.

Emiko is my best friend.

Believing that failure is a stepping stone to success, he challenged again.

Believing that failure leads to success, he continued to challenge himself over and over again.

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.

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

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

Please respond as soon as possible.

This metal has very high malleability.