Not once has she given in to any difficulty in her life and that's _____ she is a strongwilled woman.
| A．why | B．when |
| C．because | D．where |
He got up late and hurried to his office, ________ the breakfast untouched.
| A．left | B．leaving | C．to leave | D．leave |
We _________ the difficulty together, but why didn’t you tell me?
| A．should face | B．might face | C．must have faced | D．could have faced |
________ at the door before you enter my room, please.
| A．Knock | B．Knocking | C．Knocked | D．To knock |
________ with care, one tin will last for six weeks.
| A．Use | B．Using | C．Used | D．To use |
— Can I have a day off tomorrow, Mr. Johnson?
— ________. I can manage without you.
| A．Forget it. | B．I’m afraid not. | C．It depends. | D．Of course. |