If we work with a strong will, we can overcome any difficulty, ________ great it is.
| A．what | B．how | C．however | D．whatever |
If I hadn't been lucky enough to meet you, I really __________ what I would have done.
| A．don't know | B．hadn't known |
| C．wasn't knowing | D．wouldn't know |
The company __________ a rise in salary for years, but nothing has happened.
| A．promises | B．promised |
| C．has promised | D．has been promising |
I'm glad to see that you __________ a lot of progress since I__________ you last.
| A．will make; have met | B．have been making; met |
| C．had made; met | D．have made; meeting |
—Did you find the missing couple in the mountain yesterday?
—No, but we __________ to get in touch with them ever since.
| A．have tried | B．have been trying | C．had tried | D．had been trying |
__________ my sister three times today but her line was always busy every time I phoned her then.
| A．I'd phoned | B．I've been phoning | C．I've phoned | D．I was phoning |