单选题 In another institute study, 35% of U. S. employees said they had health care responsibilities during the last year. It can be episodic, unpredictable and very ______.
【正确答案】 C
【答案解析】[解析] 与空格处并列单词“episodic，unpredictable”的词性都为形容词，据此可以推知空格处应填的单词形式为形容词。此处是说“它可能是偶发的、不可预测的并且压力很大的”，C项“stressful有压力的”正确。