1. [单选题]人工呼吸法采用口对口吹气时,以看到( )为有效指征。
A. 腹部膨隆
B. 口腔扩张
C. 胸廓扩张及听到呼吸音
2. [单选题]An electrical device which employs a stationary armature and a rotating electromagnetic field is used aboard as a
A. magnetic amplifier
B. ship's service alternator
C. three-wire DC generator
D. saturable core reactor