There are certain _________ when you must interrupt people who are in the middle of doing something.
A.conditionsB.situationsC.occasionsD.environments在线课程C
occasion“场合，时刻”；condition“条件”；situation“位置，形式”；environment“环境”。句意：“有些时刻你必须打断那些正在忙着事儿的人。”故选C。