.
No matter how great the difficulty is, it can’t _____the experts from finishing the project on time.
| A．hold back | B．hold up | C．hold out | D．hold on |
After graduation she reached a point in her career __________ she had to decide what to do.
| A．that | B．what |
| C．which | D．where |
Edward, you play so well. But I ________ you played the piano.
| A．didn’t know | B．hadn’t known |
| C．don’t know | D．haven’t known |
Not until I began to work ________ how much time I had wasted.
| A．didn’t I realize | B．did I realize |
| C．I didn’t realize | D．I realize |
Little ________ about his own safety, though he was in great danger himself.
| A．does he care | B．did he care |
| C．he cares | D．he cared |
Not a single song ________ at yesterday’s party.
| A．she sang | B．sang she |
| C．did she sing | D．she did sing |