So suddenly_______that the animals in the zoo looked very frightened during the total solar eclipse.
| A．did the sky turn dark | B．the sky did turn dark |
| C．turned the sky dark | D．was the sky turned dark |
You can only be sure of you have at present; you cannot be sure of something ___ you might get in the future.
| A．that; what | B．what; / | C．which; that | D．/; that |
The practice of hanging clothes across the street is a common _________ in many parts of the city.
| A．look | B．sign | C．sight | D．appearance |
-- Bill, if it doesn't rain, we can go straight on and spend more time in Vienna.
-- ___ I just want to hear Mozart.
| A．Well done ! | B．No problem. | C．That' s great! | D．That' s it. |
-- Robert is indeed a wise man.
-- Oh, yes. How often I have regretted _________ his advice!
| A．" to take | B．taking | C．not to take | D．not taking |
John received an invitation to dinner, and with his work ________, he gladly accepted it.
| A．finished | B．finishing | C．having finished | D．was finished |