己内酰胺装置加氢系统催化剂过滤器清洗工作不得半途停止，以防止催化剂干燥后自燃。
参考答案：对
It was not until 3 days later that the boy came back to life and explained to the police what_______ to him.
A．was happening
B．was to happen
C．had happened
D．has happened
急诊护士对病人评估后，认为主要护理诊断是()。
A．活动无耐力
B．低效性呼吸形态
C．潜发并发症——感染
D．焦虑
E．疼痛
