If we _________ now to protect the environment, we’ll live to regret it.
| A．hadn’t acted | B．haven’t acted | C．don’t act | D．won’t act |
The hard part in our life is not making the decision but living with .
| A．one | B．that |
| C．the one | D．it |
---- Remember the first time you ____ her?
----Sure, she was singing on the stage.
| A．had met | B．met |
| C．would meet | D．were meeting |
Left ____ in the reading room alone quite by accident, the boy felt nervous.
| A．locking | B．having locked |
| C．to lock | D．locked |
I _____ to my cousin’s birthday party last night, but I was not available.
| A．went | B．had gone |
| C．would have gone | D．would go |
It was a pity that the policeman failed to find such a person ____ had been
described by the witness.
| A．that | B．what | C．as | D．which |