按《INCOTERMS2000》，F组术语均由买方负责订立运输合同，C组术语均由卖方

已知P（3a-9，2a-10）在第四象限，化简|a-3|+|a-5|等于______．

90年代中期，移民数对人口总增长量影响最大的是（）。

A．亚洲

B．欧洲

C．北美洲

D．大洋洲

口服脊灰疫苗应注意哪些事项？

呈扁椭圆形，外皮红棕色，顶端尖，中部膨大，基部钝圆而稍偏斜，边缘较薄，该药材是（）

A.苦杏仁

B.郁李仁

C.桃仁

D.酸枣仁

E.薏苡仁

In object-oriented (51) , objects can be viewed as reusable components, and once the programmer has developed a (52) of these components, he can (53) the amount of new coding required. But (52) a (54) is no simple task because the integrity of the Original software design is critical. Reusability can be a mixed blessing for user, too, as a programmer has to be able to find the object he needs. But if (55) is your aim, reusability is worth the risk.

A．complexity

B．creating

C．indisposing

D．library

E．maximize

F．minimize

G．reading

H．procedure

I．productivity

J．programming K. security L. using