—Hello! May I speak to Alice?—Sorry, she _____ Shanghai.
A:have gone to
B:has been to
C:has been in
D:has gone to
青霉素等抗生素能用来治疗疾病,下列有关抗生素的叙述中正确的是( )
下列图形是电与磁中的几个实验,能反映电动机工作原理的是( )