要求提供稳定的交流电输入,其输入电压允许波动范围为±5%。
参考答案:错
Those who _____ great interest in English will learn it well. [ ]
A. has
B. have
C. had
D. has had
应用血药扩张剂时应注意()。
A.必须在补足有效血容量的基础上用
B.先慢后快,由低浓度开始
C.常规剂量无效,则加大剂量
D.必要时与缩血管药物合用
E.纠正酸中毒及电解质紊乱