Mike runs _____ Mary.[ ]
A. as fast as
B. three times as fast as
C. three times faster
答案:A
左输尿管结石嵌顿可表现为
A.右下腹剧痛B.血尿C.膈下游离气体D.血淀粉酶升高
LC并联谐振回路在谐振频率点上阻抗达到()。
A.最大值
B.最小值
C.0