Walking alone in the dark，the boy whistled to ________ his courage.
| A．hold up | B．keep up |
| C．set up | D．take up |
It was not until near the end of the lettershe mentioned her own plan.
| A．that |
| B．where |
| C．why |
| D．when |
It is by no means clear ______ the president can do to end the strike．（2012．全国新课标Ⅱ）
| A．how |
| B．which |
| C．that |
| D．what |
It remains to be seen ______ the newly formed committee’s policy can be put into practice. (2013 .陕西)
| A．that |
| B．which |
| C．what |
| D．whether |
It was only after he had read the papers ______ Mr. Gross realized the task before him was extremely difficult to complete. (2013 .全国新课标Ⅱ)
| A．when |
| B．that |
| C．which |
| D．what |
John’s success has nothing to do with good luck. It is years of hard work______ has made him what he is today. (2011 .湖南)
| A．why |
| B．when |
| C．which |
| D．that |