早期妊娠利用超声检测技术最先显示的是（）
A.胎囊
B.卵黄囊
C.胚芽
D.桑葚胚
E.双顶颈
参考答案：A
What is Lynn going to do?[ ]
A. She is going to open her gift.
B. She is opening her gift.
C. She opens her gift.
脊柱腰椎段活动受限常见于（）。
A.腰椎间盘突出
B.胸椎椎管狭窄
C.腰部肌纤维织炎及韧带受损
D.腰椎结核或肿瘤
E.腰椎骨折或脱位
