Questions

The logic in the given puzzle is 

Addition of numeric values of corresponding letters in the first three figures gives respective corresponding letter in fourth figure. 

i.e, A = 1 , W = 23 , B = 2 => 2 + 1 + 23 =26 = 'Z'

Similarly, L = 12, K = 11 , A = 1 => 1 + 11 + 12 = 24 = 'X'

Here the missing letter is 'X'.

When the OS at the explicit request of another process creates a process, this action is called process spawning.

Hence, soil erosion on hillslopes can be checked by Terrace cultivation.

Repetitive Strain Injury

Given 

1 = 1 => 1 x 11 = 11

2 = 22 => 2 x 11 = 22

3 = 33 => 3 x 11 = 33

...

...

Similarly,

11 => 11 x 11 = 121.