The experiment shows that proper amounts of exercise, if _____ regularly, can improve our health.
| A．being carried out | B．carrying out | C．carried out | D．to carry out |
_____ you make a little room for me?
| A．Should | B．Could | C．May | D．Must |
I am told that her father is in London and ______ a dry-goods store.
| A．has kept | B．kept | C．keeps | D．had kept |
He ______ English for six years by the time he takes his examination.
| A．was studying | B．would have been studying |
| C．had been studying | D．will have been studying |
George has arrived, but I did not know he ______ until yesterday.
| A．comes | B．will come | C．is coming | D．was coming |
It ______ six years since they last saw each other.
| A．was | B．had been | C．is | D．would have been |