临床上可代替去甲肾上腺素用于各种休克早期的药物是（）。
A.麻黄碱
B.肾上腺素
C.间羟胺
D.异丙肾上腺素
E.去甲肾上腺素
参考答案：C
In order to improve English，________.
A．Jenny’s father bought her a lot of tapes
B．Jenny bought a lot of tapes for herself
C．a lot of tapes were bought by Jenny
D．a lot of tapes were bought by Jenny’s father
人体进入外磁场后，质子磁矩重新排列，产生一个与外磁场磁力线方向一致的净磁矢量，称为（）
A.纵向磁化
B.横向磁化
C.磁共振现象
D.MR信号
E.弛豫
