Jawaban:

1. The agent is expressed when it is a proper name indicating an artist, an inventor, a discoverer, or an innovator.

a. The Mona Lisa was painted by Leonardo da Vinci.

b. The Americas were discovered by Christopher Columbus.

c. The first computer was built by Charles Babbage.

d. Rubber was first vulcanized by Charles Goodyear.

2. The agent is expressed when it is an indefinite noun phrase conveying new information that the speaker/writer thinks is important enough to mention.

a. These works of art were all produced by a woman.

b. The corner store was robbed by a masked gunman.

3. The agent is expressed when it is an unexpected inanimate noun.

a. Thirteen people were injured by a tornado in Florida.

b. All the lights in this building are controlled by computers.

Penjelasan:

Sorry if i wrong

I hope this can help you ^^