软组织血管瘤MRI最有价值的征象是（）
A.短T2低信号环
B.短T1、长T2病变
C.占位效应明显
D.流空现象明显
E.短T1、短T2病变
参考答案：A
--I went to work on foot yesterday, though it was raining cats and dogs.
---You __________ a bus. You were likely to get a cold.
A．must have taken
B．would take
C．could take
D．should have taken
下面表示中压蒸汽的符号是（）。
A.SL
B.SM
C.SH
D.SQ
