He was observing birds using his new binoculars.

He decided to try hypnotherapy.

In physics, momentum is defined as the product of the mass and velocity of an object.

This new song will be released as a double A-side single.

I bought a new measuring spoon.

I used double-sided tape to stick the poster on the wall.

Watching his graduation ceremony, I was filled with immeasurable deep emotion.

Amphoteric oxides have the characteristic of reacting with both acids and bases.

Aluminum is an amphoteric oxide, it reacts with both acids and bases.

It's difficult to remember the units of weights and measures.