A true friend is the one that is coming in the door while else is going out.
Einstein liked Bose’s paper so much that he ___ his own work and translated it into German.
The sentence wants ____ once more.
--Why are you so anxious? --It isn’t your problem ____.
The two sportsmen congratulated each other ____ winning the match by shaking hands.
He began to take political science _________ only when he left school.