胰腺癌CT主要的直接征象是哪项（）
A.肿瘤侵犯胰周脏器
B.胰管阻塞
C.胆总管阻塞
D.胰腺局部增大、肿块形成
E.肿瘤侵犯胰周血管
参考答案：D
对于人胎盘生乳素不恰当的是（）
A.由细胞滋养细胞分泌
B.至妊娠34～36周分泌达高峰
C.分子量约2.2×104
D.为不含糖分子的单链多肽激素
E.产后迅速下降，产后7小时即测不出
Which of the following statements is true about his friend
A．Writing exhausts his friend.
B．His friend collects a lot of things to write.
C．His friend always has enough material to write on.
D．His friend is doing research to write a paper.
