频谱多普勒超声可直接测量的血流参数是
A.阻力指数(RI)B.压力阶差(PG)C.搏动指数(PI)D.收缩/舒张期速度比(S/D)E.收缩期峰值速度(Vs)
参考答案:E
下列各组离子一定能大量共存的是 [ ]
A.在含有大量AlO2-的溶液中:NH4+、Na+、Cl-、H+
B.在强碱溶液中:Na+、K+、CO32-、NO3-
C.在PH=12的溶液中:NH4+、Na+、SO32-、Cl-
D.在c(H+)=0.1mol·L-1的溶液中:K+、I-、Cl-、NO3-
He did not write _________,though(尽管)he had______ 。
A.careful enough; enough time
B.carefully enough;enough time
C.enough careful;enough time
D.enough carefully; time enough