A Doctor always sneezes before the rain. Doctor sneezes, Will it rain?

I am a seven-letter word but if you remove four of my letters I will have one left. What word am I?

You need to complete the maze by entering from the entrance marked below in the figure near the yellow circle, bottom left and leaving from the exit point near the green circle, bottom middle.

Rule of Game: You can move only by exchanging green and yellow circles.

Using eight eights and addition only, can you make 1000?

Alpha is Beta's sister.

Gamma is a Beta mother.

Delta is Gamma's father.

Tango is Delta's mother.

Then,

How is Alpha related to Delta?

Find the missing letter in the last circle logically in the given below picture.

Make eight squares by moving only two matchsticks.
Note- Square can be of different sizes.

I never was there, I am always to be.
You have never ever seen me, not ever you will.
Yet I am the confidence of everyone.

Who Am I?

A number can be multiplied by multiple of nine
i.e 9 18 27 36 45 ...

and the resulting number consist of only one digit.

Can you identify the number ?

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