It was not until he arrived at the office_____ realized he had forgotten the key. 
| A．and he | B．when he | C．that he | D．he |
In front of the Great Pyramid, Mr Lee stood _____ its great height, and asked many questions.
| A．to gaze up at | B．to gaze down at | C．gazing up at | D．gazing down at |
Mom believes that those words put to paper two centuries ago really _____ something.
| A．mean | B．represent | C．tell | D．say |
We know _____America is great not because it is perfect but because it can always be made better and _____ the unfinished work of perfecting the union falls to each of its citizens.
| A．不填；不填 | B．that ; that | C．that ; 不填 | D．不填；which |
If Doric continues doing things like that, he ______ face the music one day！
| A．can | B．should | C．would | D．shall |
I know you have eaten all sorts of junk food your mother and I probably _____ you have.
| A．shouldn’t let | B．can’t let | C．couldn’t have let | D．shouldn’t have let |