Last term our maths teacher set so difficult an examination problem ______none of us worked out.
| A．that | B．as | C．so that | D．which |
He could have finished it on , but he was ill last week and that was why he fell behind.
| A．schedule | B．disadvantage | C．purpose | D．timetable |
The witness was expected to give the police a description of what had happened, but he was too scared to do any help.
| A．special | B．particular | C．complex | D．especial |
Mistakes don’t just happen; they occur for a reason. Find out the reason and then making the mistake becomes .
| A．favorable | B．precious | C．essential | D．worthwhile |
Nothing can separate the two, because they have a friendship foundation dating back to their childhood when they had to depend on each other to survive in the war.
| A．basic | B．solid | C．unique | D．slide |
He is thinking of his business while his father is strongly against it for fear of the further positive effect of the global economic crisis. .
| A．expanding | B．carrying | C．exploding | D．spreading |