With sufficient scientific information a manned trip to Mars should be _____.
| A．obtainable | B．potential | C．considerable | D．feasible |
I like these English songs and they ________ many times on the radio.
| A．taught | B．have taught |
| C．are taught | D．have been taught |
Now the world’s attention ________ the stock markets，as they have a great influence on the world’s economy.
| A．is fixing on | B．has fixed on |
| C．is being fixed on | D．had been fixed on |
Whatever you have found，you should give it back to whomever it ________.
| A．is belonged to | B．is belonging to |
| C．belonged to | D．belongs to |
I feel so excited! At this time tomorrow morning I ________ to Shanghai.(2012·辽宁，31)
| A．will be flying | B．will fly |
| C．have been flying | D．have flown |
The letters for the boss________on his desk but he didn’t read them until three days later. (2012·天津，2)
| A．were put | B．was put |
| C．put | D．has put |