The manager didn’t turn up ______ Peter agreed to sign the contract.[ ]

They’re arguing on who, on earth, is known for the great discovery penicillin, an effective bacteria killer.

Some of the wolvesthere _________ their fur.

When you talk to people, you’d better ________ to show that you’re friendly to them.

Your boss looks rather a kind person. —But in fact he is cold and hard on us. You ______ believe it!