What is the singular and plural for bookshelf

a phrase is a set of word that make a sense, an expression formed by two or more words.

" teacher´s dictum on the possession of human "

" made a pile practicing "

" lived to an impressive age and dies "

a clause, in a grammar way is a series of words that have a complete meaning.

" was irritated by the persecution of those who called themselves "

1.c

2.a

3.d