The process of(72)schedule activity durations uses information on schedule activity scope of work，required resource types，estimated resource quantities，and resource calendars with resource availabilities． A．estimating B．defining C．planning D．sequencing

The additional drugs may result in drug effects or durations of drug aciton quite dissimilar to that found when each is administered alone. A: 同时服用多种药物所产生的药效和持效期与他们各自单独服用时可能有很大不同。 B: 额外的药物可能导致药效或者药性相当不同与那种被发现当单独服用的效果。