抗菌谱是
A.药物的治疗指数
B.药物的抗菌范围
C.药物的抗菌能力
D.抗菌药的治疗效果
E.抗菌药的适应证
参考答案:B
解析: 抗菌谱是抗菌药抑制或杀灭病原微生物的范围。
— The window must have taken you quite a lot of time that day.
— You are right. They _____ for weeks.
[ ]
A. haven't been cleaned
B. hadn't been cleaned
C. didn't' clean
D. haven't cleaned
在电动机继电器接触器控制电路中,自锁环节的功能是()。
A.保证可靠停车
B.保证起动后持续运行
C.兼有点动功能
D.短路保护