不符合腹腔炎性淋巴结肿大声像图特点的是()
A.大多呈圆形或椭圆形
B.相互融合,失去正常淋巴结形态
C.包膜清晰
D.淋巴门回声清晰
E.实质多为均匀的低回声
参考答案:B
Why do bond portfolio managers use the concept of duration()
A. It allows structuring a portfolio to take advantage of changes in credit quality.
B. It enables direct comparisons between bond issues with different levels of risk.
C. It assesses the time element of bonds in terms of both coupon and term to maturity.
测量配线绝缘时如何选用兆欧表?