While building a tunnel through the mountains, ______.
| A．an underground lake was discovered | B．there was an underground lake discovered |
| C．a lake was discovered underground | D．the workers discovered an underground lake |
-I remember you were a talented pianist at college. Can you play the piano for me?
- Sorry, Ithe piano for years.
| A． | don't play | B． | wasn't playing | C． | haven't played | D． | hadn't played |
hard you try, it is difficult to lose weight without cutting down the amount you eat.
| A．However | B．Whatever | C．Whichever | D．Whenever |
The lecture,at 7:00 pm laze night, was followed by an observation of the moon with telescopes.
| A． | starting | B． | being started | C． | to start | D． | to be started |
It was not until I came here _____I realized this place was famous for not only its beauty but also its weather.
| A．who | B．that | C．where | D．before |
Sorry, I am too busy now. If Itime, I would certainly go for an outing with you.
| A． | have had | B． | had had | C． | have | D． | had |