You could say they were flying, or they were hovering, or gliding
Imperative sentences usually end with a period but can occasionally end with an exclamation point. These sentences are sometimes referred to as directives because they provide direction to whomever is being addressed.
Below, you'll find some examples of imperative sentences. Note that each line is issuing a command of some sort.
Pass the salt.
Move out of my way!
Shut the front door.
Find my leather jacket.
Be there at five.
Clean your room.
Complete these by tomorrow.
Consider the red dress.
Wait for me.
Get out!
Make sure you pack warm clothes.
Choose Eamonn, not Seamus.
Please be quiet.
Be nice to your friends.
Play ball!
The correct answer is D. because it gives no indication of a place
The correct answer is predicate adjective.
A predicate adjective is the first adjective found after a linking verb (used to link, or connect two parts of a sentence). In the sentence above, the linking verb is <em>seemed </em>and the first (and the only) adjective after it is the word rapid.
There are no objects in the sentence so B and D are incorrect, and given that rapid is an adjective rather than a noun, A is also incorrect.