正常妊娠孕卵在什么条件下着床（）

A.排卵后第2～3天的子宫内膜

B.孕妇体内有足够的孕酮

C.子宫内膜出现蜕膜反应时

D.受精卵在桑葚期着床

E.受精卵的透明带尚存在时

Accelerated analysis approaches emphasize the construction of (8) to more rapidly identify business and user requirements for a new system. As an accelerated analysis technology, (9) reads the program code and automatically generates the equivalent system model, and the code can be obtained from (10) All system analysis approaches require some form of (11) which includes those techniques to be used to identify or extract system problems and solution requirements from user community. (12) is a classical set of techniques used to collect information about system problems, opportunities, solution requirements, and priorities.

8（）

A. object models

B. prototypes

C. use cases

D. components