_______ difficult the task may be, we must finish it on time, because we can’t meet such a precious opportunity _______ we have expected.
| A．Whatever; that | B．However; as |
| C．However; that | D．Whatever; which |
My mother asked me to repeat ________ phone number ________ second time so that she could write it down.
| A．the; a | B．a; a | C．a; the | D．the; the |
It never occurred to meyou could succeed in persuading him to change his mind.
| A．which | B．what | C．that | D．if |
The momentJohn will never forget isMr. Smith gave him a lot of valuable advice on how to improve his writing.
| A．that; that | B．that; when | C．when; that | D．when; when |
China first agreedthe six-party talks about North Korea nuclear weapons program.
| A．to attend | B．to join | C．to participate in | D．to take a part |
It is wise of you towell trained workers for untrained ones in your workshop.
| A．substitute | B．change | C．exchange | D．employ |