It seems that living green is _______ easy and affordable. A small step makes a big difference.
| A．generally | B．fortunately |
| C．hardly | D．surprisingly |
I’m sure I _____ her four years ago.
| A．have seen | B．saw | C．had seen | D．will see |
An unexpected heavy rain caused severe flooding, and the water _____ all the time.
| A．rose | B．raised | C．was rising | D．was raising |
_____ a noise just then?
| A．Have you heard | B．Were you hearing |
| C．Are you hearing | D．Did you hear |
Great changes _____ in the last twenty years in China.
| A．took place | B．have taken place |
| C．were taking place | D．have been taken place |
— Where _____?
— I got stuck in the heavy traffic. I _____ here earlier.
| A．did you go； had arrived | B．have you been； would have been |
| C．were you； would come | D．are you； was |