What time is it?[ ]
A. It's 7 o'clock.
B. It's 7.
C. At 7:00.
D. On 7:00.
答案:A
CT辐射特点的叙述,错误的是
A.窄束X线
B.管电压低
C.滤过要求高
D.单一高能射线
E.射线转换效率高
自己能在家里进行药物流产吗?