引起艾滋病的病原体是人类免疫缺陷病毒,简称HIV。
参考答案:对
妊娠几周后,B型超声可作为产前诊断项目()
A.5周
B.12周
C.16周
D.24周
E.28周
No matter what they say, I’ll ___ my opinion.
A.stick to
B.persist in
C.insist on
D.hold up