5) The girl was sent to the hospital, seriously injured in the car accident.

2.Passive verb-ed phrases can express time, reason and condition. We can use adverbial clauses(状语从句) to rewrite the phrases.

1) time

Seen from the hill, the park looks very beautiful.

= When the park is seen from the hill, it looks very beautiful.

When completed, the museum will be open to the public.

= When it is completed, the museum will be open to the public.

Once seen, it can never be forgotten. = Once it is seen, it can never be forgotten.

2) reason

Frightened by the thunder and lightning in the night, the girl did not dare sleep alone in her own room.

= Because she was frightened by the thunder and lightning in the night, the girl did not dare sleep alone in her own room.

Lost in thought, he almost ran into the car in front of him.

= Because he was lost in thought, he almost ran into the car in front of him.

3) condition

Given more time, we could do it much better.

= If we were given more time, we could do it much better.

Unless invited to speak, you should remain silent at the conference.

= Unless you are invited to speak, you should remain silent at the conference.

Compared with other professors, she was an excellent speaker.

= If she was compared with other professors...

3. Understood subject(逻辑主语)

1)The understood subject is usually the same as the subject of the main clause. (refer to the above sentences)

2) When verb-ed is used as adverbial(状语) or predicative(表语), its understood subject is the subject of the main sentence.

She became discouraged at the news.