With sufficient scientific information a manned trip to Mars should be _____.
| A．obtainable | B．potential | C．considerable | D．feasible |
In the last decade, disasters have become increasingly common. It’s high time that we ______these issues more seriously.
| A．took | B．have taken | C．had taken | D．are taking |
_________ you are, __________ mistakes you’ll make.
| A．The less careful; the less | B．The less careful; more |
| C．The more careful; the fewer | D．The more careful; the more |
Although they plant trees in this area every year, the tops of hills are still ______.
| A．blank | B．hollow | C．vacant | D．bare |
People have heard _______ the President has said; they are waiting to see _______ he will do.
| A．how, how | B．what, what |
| C．when, how | D．that, what |
—How do you like the food in this restaurant？
—Oh, _______. We couldn’t have found a worse place.
| A．too bad | B．sorry |
| C．wonderful | D．impossible |