该患儿突然缺氧发作，首要的急救措施是
A．口对口呼吸B．面罩给氧C．鼻导管给氧D．气管插管E．静注钙剂
参考答案：A
It is in this very village , ___Mary was born 35 years ago , ___ she will build her first school ,
inspires everyone to help her .
A．where; that ; which
B．that ; that ; that
C．that ; when ; which
D．where ; when ; that
脉冲波是指振动（）有限的波动。
A、波高
B、能量
C、持续时间
D、波幅高度
