The Olympic Games ____ held every ____ years.
| A．is;four | B．are;four | C．is;five | D．are;five |
Over the past decades , sea ice _____in the Arctic as a result of global warming.
| A．had decreased | B．decreased | C．has been decreasing | D．is decreasing |
--I would why he ____so strangely these days.
--Recent pressure at study may account for his behavior.
| A．was acting | B．is acting | C．acted | D．acts |
--Please tell the court what really happened.
--Oh, I ____ , and I hit a parked car.
| A．wouldn’t pay attention | B．hadn’t paid attention |
| C．haven’t paid attention | D．wasn’t paying attention |
According to the lastest study ,the population of Xuzhou has grown to more than 30 times____it was in 1949. The figure ____to 9.5 million by the end of 2010.
| A．that , will rise | B．that ,will have risen | C．what , will rise | D．what ,will have risen |
. In September 2008 , China’s key milestone in space travel_____when Zhai Zhigang conducted the first space walk.
| A．reached | B．was reached | C．has reached | D．had been reached |