If a mirror reverses right and left, why doesn't it reverse up and down?

Given question are based on the general English alphabet. A B C D E F G H I J K L M N O P Q R S T U V W X Y Z If the first five letters of English alphabet are reversed and then next six letters are reversed, again next five letters are reversed, again next six, letters are reversed, again last four letters are reversed, then which letter will be 11th to the right of 4th letter from the left? 1) L 2) M 3) N 4) O 5) None of these

This question is based on the following alphabet series. A B C D E F G H I J K L M N O P Q R S T U V W X Y Z If the first 5 letters are written in reversed order, then the next five letters are written in reversed order and so on, which is 7th letter to the right of 9th letter from the left? 1) T 2) S 3) P 4) Q 5) None of these

This question is based on the following alphabet series. A B C D E F G H I J K L M N O P Q R S T U V W X Y Z If the first 6 letters are written in reversed order, then the next 5 letters are written in reversed order and again next 6 letters are written in reversed order then which letter is in the middle between 7th letter from the left and 12th letter from the right? 1) G 2) T 3) H 4) U 5) None of these

Assertion (A): During reverse, biasing a diode doesn't conduct current. Reason (R) : It narrows the depletion layer.

In a zener diode, break down occurs in reverse bias due to