___________ was no doubt __________ someone had broken into the store the day before.
| A．There; that | B．There; whether | C．It; that | D．It; whether |
_____, he always tries his best to complete it on time.
| A．However the task is hard | B．However hard the task is |
| C．Though hard the task is | D．Though hard is the task |
Scientific research results can now be quickly_____ to factory production.
| A．used | B．applied | C．tried | D．practiced |
After _____ seemed an endless wait, it was her turn to enter the personnel manager’s office.
| A．that | B．what | C．which | D．whether |
_____ at in this way, the present economic situation doesn't seem so gloomy.
| A．Looking | B．Looked | C．Having looked | D．To look |
I arrived at the airport so late that I _____ missed the plane.
| A．only | B．quite | C．narrowly | D．seldom |