He was observing the distant birds using binoculars.

English is widely used as a common language in the world.

He read the small print using a magnifying glass.

I used binoculars to observe birds in the mountains.

The study of phonons is an important field in physics.

That battlefield was truly a hell of agonizing cries.

He is undergoing psychotherapy to overcome anthropophobia.

He joked around and used vulgar language.

In the old days, people used to consider milk as an important source of nutrition.

Our opinions differ.