A new building _____ built last year. [ ]
A. is
B. was
C. were
D. will be
答案:B
下列何药不能用于对青霉素有耐药性的金葡菌感染:
A.庆大霉素
B.万古霉素
C.氯唑西林
D.哌拉西林
E.红霉素
多台泵串联是为了()。
A.提高压力
B.降低压力
C.提高流量
D.降低扬程