A unicellular is a one celled organism and a multicellular is a organism with 2 or more organisms
the appropriate arrangement and logical coherence of words in a sentence
Syntax is the arrangement of words, clauses, and phrases in a sentence
I would say Fact. A fact can be proven true or false. An opinion can be both true and false
Explanation:
It indicates that the word is an adjective. Joy is a noun. Joyous is an adjective.
The most famous annual festival in Wales is the Royal National Eisteddfod.