To do this, we first analyze the first letters of each of the words.
"Raining" begins with "r" as "robbing" and "refusing".
"Sailing begins with "s" as "seizing".
"Plaguing" begins with "p" as "planning".
Now, let´s take a look through the alphabet
A B C D E F G H I J K L M N O "P" Q "R" "S" T U V X W Y Z
"P" is the first letter that shows up, followed by "R" and "S".
So, for now, we have:
Plaguing, Planning, Raining, Robbing, Refusing, Sailing and Seizing.
Let´s begin with letter P, the first syllable of the 2 words beginning with P are identical, so let´s take a look on the 3rd letter. plaGuing and plaNning.
As we can see on the alphabet the letter G comes before than the letter N, so, we must organize this way.
First the word Plaguing and then the word Planning.
Let´s apply this rule for the other words and we have:
1) Plaguing; 2) Planning; 3) Raining; 4) Refusing; 5)Robbing; 6)Sailing; 7) Seizing.