安全阀的校验周期是（）一次，压力表的校验周期是（）一次。 ["每年","每半年","每季","每月"]
Having been familiar with his ability, （）. ["the manager was assigned a challenging task","the manager assign a challenging task","the board assigned him a challenging task","a challenging task was assigned to the manager"]
实词
对心脏停止跳动的触电者，通常采取人工胸外挤压法，强迫心脏跳动，挤压频率一般为每分钟（）次。 ["25","15","60","20"]
（）是构建社会主义和谐社会的两大制度。
