A: This involves
The difference between nouns plus nouns and nouns plus nouns
(1) nouns with nouns:
The former noun is an attribute. When modifying the latter noun, use a noun plus of to add a noun.
Of is the possessive case of nouns.
such as
This is the English expression of science books.
in addition
Nouns representing inanimate objects generally form a phrase with of, which can represent all relationships.
For example:
The cover of this book.
of course
Use "of+ nouns" to express relationships, and the nouns behind them can be alive or inanimate.
For example:
Inanimate: the walls of a town
The roof of the church
② "noun 1+of+ noun 2" can often be replaced by "noun 2+ noun 1";
City wall
The roof of the church
At this time, the first noun becomes an adjective, not a plural form.
This is the English expression of a math book.