About grammar...

Clause 是「子句」, 它不是完整句子, 是附於一句完整句子內, 用
於把意思說得較詳細。以下的例句子中, 紅色的是 Clause 。
1. The man who lives next door is a policeman .
2. Do you know the man talking to Ben ?
3. The boy injured in the accident was taken to hospital .
4. Having lost my key, I cannot open the door .
5. When in Rome, do as the Romans. Whatever their faults,
they are not hypocrites.
Absolute Clauses ( No. 2, 4 examples)

-----Here are two things to remember about clauses which are
absolute: the verb is a participle ( verb+ing ), and it agrees
with something in the absolute clause, not in the main clause
of the sentence.

Verbless Clauses ( No. 5 example )
-----There is no verb in the verbless clause .

Example No. 1 ----- an extra information clause
Example No. 3 ----- an 'ed' clause has a passive meaning

They are both the reduced form of the full subordinate clause.
Verbless clauses, as their name suggests, are notable for their lack of any verb form.
e.g. Anxious and fretful, she left early.

Absolute clauses are much like the -ing clause and begin with a pronoun in the genitive or objective case that seems to function as the ' subject' of the -ing verb.
e.g. Her hearing the news, she left early.