Tina was hesitating about the job offer as she did not know ______ the company was an established one.
| A．whether |
| B．what |
| C．until |
| D．although |
I smoke out of ____ habit, not for ____ pleasure; for I have been in the habit for twenty years.
| A．a; the | B．the; a | C．x; the | D．x; x |
So many uses have been discovered for this wood ____ the supply of white pine is becoming smaller and smaller.
| A．then | B．what | C．that | D．which |
The truth, Sir, is that the old man____ across the street when my car hit him.
| A．was to walk | B．had been walking | C．walked | D．was walking |
I wrote to my parents once a week,____ I was too busy with my teaching work.
| A．it | B．unless | C．when | D．as |
However, at times this balance in nature is disturbed, ____ a number of possibly unforeseen effects.
| A．lying in | B．calling in | C．taking in | D．resulting in |