Why?
We use the passive voice when we don’t want to say who or what does the action. This helps us start sentences with the most important information, especially when we don’t know, it’s obvious, or we just don’t want to say.
PASSIVE VOICE IN PRESENT SIMPLE - EXAMPLE
simple present: am/is/are + past participle
A museum _____________ by thousands of tourists.
How many languages ___________ in London - apart from English?
Answers:
is visited
are spoken
simple past: was/were + past participle
Source: https://en.islcollective.com/english-esl-video-lessons/grammar-practice/general-grammar-practice/passive-voice/725906