This virus is spreading rapidly.

There is not a single cloud in the sky.

The sky is very beautiful, isn't it?

Seeing the empty cup, he poured another cup of tea.

He can recite the poem by heart.

This winter scenery is really beautiful, isn't it?

Quantum entanglement is one of the most mysterious phenomena in physics.

The theory of quantum entanglement is one of the most complex parts of physics.

The phenomenon of quantum entanglement is a very interesting topic in physics.

Untangling her tangled hair was difficult.