利多卡因血内浓度多少时对室性心律失常有治疗作用()
A.1~5pg/ml
B.2~7pg/ml
C.8~9pg/ml
D.10~11pg/ml
E.12~15pg/ml
参考答案:A
He must be helping the old man to water the flowers, ________?[ ]
A. is he
B. isn't he
C. must he
D. mustn't he
在世界经济全球化浪潮中影响增大成为主角的是
A.高新科技
B.跨国公司
C.国际和区域性经济组织
D.发展中国家