By the time he realizes he ____into a trap, it’ll be too late for him to do anything about it.
| A．walks | B．walked | C．has walked | D．had walked |
The scientist _____ Canada and he will give us a talk when he _____ back.
| A．has gone to/comes | B．has been to/will come |
| C．has gone to/will come | D．has been to/comes |
He found his book this morning, but now he _____ his pen.
| A．loses | B．is missing | C．has lost | D．lost |
She ____ to her hometown several times.
| A．has been | B．has gone | C．went | D．is going |
It _____ Jane and Mary who helped me the other day.
| A．is | B．was | C．are | D．were |
I _____ to bed when the telephone rang.
| A．have been | B．went | C．am going | D．was going |