Most environmental problem exist because___measures for preventing them were not taken in the past
| A．adequate |
| B．enough |
| C．many |
| D．much |
You needn't have apologized for your absence—________， it's hardly your fault.
| A．therefore | B．however |
| C．meanwhile | D．besides |
Once you are ________ to smoking, it is difficult to give it up.
| A．crazy | B．addicted |
| C．fond | D．attractive |
There is no doubt that I'm trying to do what is best, but ________ I have got to consider the cost.
| A．merely | B．equally |
| C．nearly | D．mostly |
If the price of oil remains ________ for the rest of 2013, I will consider buying a new car.
| A．solid | B．specific |
| C．stubborn | D．stable |
Mike did the homework ________ it took me.
| A．onethird a time | B．onethird time |
| C．a onethird time | D．onethird the time |