电力系统发生短路时,电阻总会()。
A、减小;
B、不变;
C、增大;
D、忽大忽小。
参考答案:A
---Why was Mr. Li so happy this morning?
---Because he was with an award for excellence in teaching.
A.given
B.admired
C.honoured
D.rewarded
乌头赤石脂丸的症特征是()
A.心痛彻背,背痛彻心
B.心痛彻背,倚息不得卧
C.胸背痛,喘息短气
D.胸背痛,心中痞
E.心悬痛,心中痞