Passive Voice with 'By'

Plaza Vea is visited by thousands of people every day.

• necessary

• not necessary

Machu Picchu is studied by archeologists every year.

• necessary

• not necessary

Some money was donated by the government to the museum.

• necessary

• not necessary

The Inca empire was conquered by Spanish soldiers in the XVI century.

• necessary

• not necessary

This motorcycle is manufactured ___ 20 years ago.

• by Ducati.

• ∅

Bakery was invented ___ in France.

• by a chef

• ∅

The iPhone was invented ___ in 2007.

• by Steve Jobs and Apple

• ∅

America was discovered ___ in 1492.

• by Christopher Columbus

• ∅

The city of Puno was founded ___ in the XVII century.

• by viceroy Count of Lemos

• ∅

Natural medicine was used ___ since the beginning of mankind.

• by people

• ∅