Over the years, people have learned from ants that teamwork and perseverance are indeed two key ______ to success.
| A．certificates | B．ingredients |
| C．approaches | D．instructions |
---Is this the first time you ______ Xi’an? --- No. But ______ here, the city wasn’t so modern.
| A．have visited; the first time I came | B．visited; the first time I came |
| C．have visited; for the first time I came | D．visited; the first time I’ve come |
Jenny thinks it won’t be long ______ she is ready for her job.
| A．when | B．after | C．before | D．since |
.---Seize the chance, ______ you will regret it. --- Thank you.
| A．and | B．otherwise | C．but | D．so |
How I ______ the college students the good education they can receive!
| A．envy | B．admire |
| C．appreciate | D．enjoy |
Mary looked at _____ finished article with ______ satisfaction.
| A．/; a | B．a; the | C．the; / | D．the; a |