为提高除颤效果，应先使用（）药物将细颤转变为粗颤，然后再行电除颤。
参考答案：肾上腺素
Changing rescuers while carrying out artificial respiration should be done（）.
A.without losing the rhythm of respiration
B.only with the help of two other people
C.by not stopping the respiration for more than 5 minutes
D.at ten-minute intervals
茶树土壤养分
