DSA造影期间一般进行两次曝光，一次是在对比剂到达感兴趣区之前，另一次是在A．对比剂

Behind my apartment, there is used to be a dirty and   1.___________

messy comer. Bits of plastic bags hanged on the trees.         2.___________

Broken bottles were left laying here and there. There was      3.___________

a damaging car in the center. The whole comer gave off an     4.___________

unpleasant smell. One year ago, we decided to turn it in a      5.___________

beautiful park. Since then, great changes have been taken place  6.___________

in that comer. All the rubbish have been cleared away. Flowers  7.___________

and young trees have planted all over. Now birds come             8.___________

here to sing, children come here to play, and adults come here   9.___________

to enjoy our peaceful life. It has taken on a new look.         10.___________

对卵巢内胚窦瘤有特异性诊断价值的肿瘤标志物是（）

A.AFP

B.雌二醇

C.CA125

D.HCG

E.孕激素

乳突手术寻找鼓窦的解剖标志为（请从以下5个备选答案中选出3个正确答案）（）。

A.乳突上嵴

B.Korner隔

C.道上棘

D.筛区

E.道上三角区

导线有哪三大类？

通过航摄成1:1000的图，那么航摄比例尺范围应为( )。

A．1:2000～1:3500
B．1:3500～1:7000
C．1:7000～1:10000 D．1:10000～1:20000