Why do we preferably have round manhole covers and not square ones?

A boy was driving a car, a girl took a lift from her. She asked his name. The boy said - my name is hidden in my car’s number, find it if you can. After this, she got down Car number was [ WV733N ] Can you guess the name now?

I am a five-letter word and comprises two different vowels and three same consonants. I am so strong that I can spoil your entire work.

Can you find out who am I?

What's the only room from which no one can enter or leave

People make me, save me, change me, raise me. What am I?

What makes this number unique: 8,549,176,320?

Find the next number in the series.
1 10 24 43 67 ?

The dirtier I get, the whiter I look. Who am I?

The following four words might seem abrupt to you. But you can make them meaningful by just adding vowels.
RDSH
GGPLNT
TMT
NN

Hint: All of them are vegetables.

Cristina was born in 1888. She just had her 30th birthday today how did that happen?