消化道常用造影剂是______
A．碘化油 B．泛影葡胺 C．优维显 D．硫酸钡 E．阿米培克
参考答案：D
Jenny says she might _____ a doctor in the future. [ ]
A. is
B. be
C. makes
D. to be
螺线管通电后，小磁针静止时指向如图所示，请在图中标出通电螺线管的N、S极，并标出电源的正、负极．
