Complete the sci-fi author's manuscript by dragging the correct passive voice phrases into the story.

The majestic mothership was built by a highly advanced alien race centuries ago. Today, unsuspecting humans are observed from space while they struggle to parallel park their tiny vehicles.

The majestic mothership was built by a highly advanced alien race centuries ago.

The phrase "centuries ago" requires the past tense. "Mothership" is singular, so the correct passive form is "was built".

Today, unsuspecting humans are observed from space while they struggle to parallel park their tiny vehicles.

The word "Today" sets a present tense context. "Humans" is a plural subject, making the present plural passive "are observed" the correct choice.