Peter is my best friend. He often helps___ science.
He decided to study hard__________ catch up with others.
This dress still looks pretty on you, _______ it is out of style.
—Mike, could you tell me if Mary to my party tomorrow? —I think she will if she time.
Jim came into the room ______ Millie sat down on the chair last night.
---Could you tell me_________?---Sorry, I have no idea, either. You can ask the policeman over there.