励磁自动调节应保证发电机端电压静差率小于()倍。
A.0.5%
B.1%
C.1.5%
D.2%
参考答案:B
I'm sorry to have you _____ so long. [ ]
A. waited
B. to wait
C. waiting
D. to be waiting
治疗上实下虚,痰涎壅盛之喘咳,应首选
A.桑菊饮B.定喘汤C.养阴清肺汤D.苏子降气汤E.麻黄汤