part a identify participle or participle phrase and the word it modifies
1)Taken for granted by most of us, paper is an esseantial part of our lives
2)The papeer used today has developed over many centuries
3)Ancient Egyptians wrote on a sheet formed from stalks of a reed
4)The reed, called papyrus, grew along the Nile River
participle:called papyrus, modfies:reed
5)Cut down, the reed stalkswere sliced into thin strips
participle:reed stalks, modifies:papyrus strips
6)can you imagine the laborers working in the hot sun
7)the papyrus stripa, laid in crisscross layers, were pressed together into fairly smooth sheets
part.:laid in crisscross layers
modifies:papyrus strips
8)Modern paper, however, started with a chines inventor serving emperos he di
9)The inventor's was Cail Lun, also spelled Ts'ai Lun.
10)Arabs fighting near chinas borders captured chinese papermakers and brought their art to the west
4 and 7 are correct.
Participles are verb forms. They are a verb's 3rd and 4th principal parts.
Examples, listing 1st, 2nd, 3rd, and 4th principal parts:
walk - walked - walking - walked
speak - spoke - speaking - spoken
teach - taught - teaching - taught
drive - drove - driving - driven
go - went - going - gone
do - did - doing - done
http://grammar.ccc.commnet.edu/grammar/verbs.htm
Scroll down to Four Verb Forms to see additional examples.
Now go back into those sentences and find 1) verb forms that fit either the 3rd or 4th principal part's pattern and 2) are not the main verb of the sentence.
1) Participle: Taken for granted
Word it modifies: paper
2) Participle: used
Word it modifies: paper
3) Participle: written
Word it modifies: Egyptians
4) Participle: called papyrus
Word it modifies: reed
5) Participle: Cut down
Word it modifies: reed stalks
6) No participles or participle phrases in this sentence
7) Participle: laid in crisscross layers
Word it modifies: papyrus strips
8) Participle: serving
Word it modifies: inventor
9) No participle or participle phrase in this sentence
10) Participle: fighting
Word it modifies: Arabs