这位歌手凭借她不可否认的明星魅力赢得了大批粉丝。

The singer gained many fans thanks to her undeniable ___star appeal.

医生建议使用腰麻进行剖腹产手术。

The doctor recommended ___SA for the cesarean section.

医生解释说窦房结控制着心跳的节律。

The doctor explained that the ___s-a node controls the heart's rhythm.