— How was everything going when you studied abroad?— It was a difficult time at first, but things ______ fine finally.
-Please keep the secret _______me. -OK. I’ll keep it _______myself.
Why was the house on fire? _______ lightning hit it.
Please _________for my car.
He found _________important to protect wild birds.
The teacher asked us to keep quiet. Which kind of structures does the sentence belong to?