20．Only when ____________ possible to settle the problem.

　 A．does the chief editor come will it be

　 B．the chief editor comes will it be

　 C．has the chief editor come it will be

　 D．the chief editor comes it will be

19．Determination is a kind of basic quality and this is ______it takes to do jobs well.

　 　 A．why　　　　　　　　　　 B．that　　　　　　　　　　 C．which　　　　　　　　 D．what