Questions

It is very hard to catch breathe when you run fast.

A Skeleton is what is whole but incomplete, have no eyes, yet can see. We can see, and see right through it. The largest part is one fourth of what it once was i.e body.

When modifiers are misplaced or put in the wrong place, things can get quite confusing. A modifier adds detail or limits or changes the meaning of another word or phrase. 

Here Option A) "Covered in fluffiness, the couple played with the kitten" is the ony sentence contains a misplaced modifier. In the sentence, it gives the meaning that the couple are fluffy not the kitten.

Primary key helps us to identify a row uniquely in a relation