This bridgehead is in a strategically important position.

He will participate in the swimming competition.

He decided to take up a teaching position.

He went to Africa for evangelism.

All of my parents and siblings are healthy and happy.

He was hospitalized due to pleurisy.

He read the small print using a magnifying glass.

Even after a day passed, there was no reply from him.

He was observing birds using his new binoculars.

Phonons are an important concept in solid state physics.