Both can be used depending on the subject of communication.
In certain situations like Report Writing, Precis Writing, Business writing etc. Passive voice is preferred.
In most of the cases the Doer of the action is not mentioned in the Passive Voice.
The sentence "Sentences can be written in active and passive voices" is a declarative sentence written in passive voice.
No. Every verb in the sentence given is in the active, not the passive, voice
That sentence is written in active voice. "The safety features of the plane were described by the the flight attendant" is passive voice.
active voice
passive active A+
"The policeman chased after Fred" is active voice.
change into active voice this essay was written by him
Passive voice
Sentences written in active voice are clearer and more straightforward than those written in passive voice. In active voice, the subject is doing something rather than having something done to them. An example of passive voice is, "He was reading the book his cousin had written." Active voice may read, "He's reading the book his cousin wrote."
No, this sentence is written in passive voice: He was appointed to the team by his supervisor. Active voice: His supervisor appointed him to the team.
It is in the active voice.
First, "stone like" should be hyphenated: "stone-like." The sentence as written is in active voice. If it were written in passive voice it would be: "Stone-like structures are built by corals."