Can you tell me ______?

____ troubles me most right now is____ I can’t remember where I have put my car keys.       

The man standing on the desk held the view        he was right.

Only by working hard and never giving up       our goals.

Recently there have been many occasions____ you have attended events on your own.

He kept smiling secretly and we were all wondering      that made him so happy.

          that young babies learn to do things because certain acts lead to awards.

He was driving home on the highway last night when he was stopped by a policeman，         .

Are you ______ your son has difficulty in studying at school?

It was after he got what he had wanted very much _______ he realized it was not important.