21．I'm sorry you so long, but it'll still be some time before Jim gets back.
A．wait B．waited C．had waited D．have been waiting
22．When I was a child，my father ．read me a story at night before bedtime
A．would B．should C．could D．might
23．Martin drove along ．he found a convenient parking place
A．after B．when C．until D．since
