After the new technique was introduced，the factory produced ___ tractors in 1988 as the year before.
| A．as twice many | B．as many twice | C．twice as many | D．twice many as |
He made no preparation for the job interview in advance, which might_____ his failure in it.
| A．bring up | B．account for | C．contribute to | D．agree with |
The doctor’s first reaction was a strange ______ of joy and anger.
| A．mass | B．mixture | C．collection | D．number |
As is known to us, the new minister will be ______ in office by the Queen.
| A．recognized | B．understood | C．confirmed | D．permitted |
______ is known to us all is that the 2016 Olympic Games will take place in Rio de Janeiro.
| A．It | B．Which | C．As | D．What |
What the teachers really doubt is ______ this student will get on well with the other students after he was caught stealing.
| A．whether | B．that | C．when | D．why |