______ it have been the failure to pick up directions from the ground control that caused the air crash?
| A．Must | B．Could | C．Would | D．Should |
－How did you find those days？
－The days________ we spent together on the farm are not easy________．
| A．that；to forget | B．when；to be forgotten |
| C．when；to forget | D．that；to be forgotten |
George once told me that he would visit our house，but，for various reasons，he ________so far．
| A．didn't | B．hasn't | C．hadn't | D．wouldn't |
－Look，here________．
－Oh，it's my secretary．But I________ him to pick me up at seven o'clock．
| A．comes a car；had told | B．comes a car；told |
| C．does a car come；had told | D．a car comes；to |
－Personally，I believe I can do it well on my own．
－________Selfconfidence is the first secret of success．
| A．It's up to you． | B．Take it easy． |
| C．Let' s get going． | D．I'm with you on that． |
Although most of them have no doubt ____ he will pass the exam, I still think there is something about _____ he has really got everything ready．
| A．that; that | B．whether; that |
| C．that; whether | D．whether; whether |