人胚的主要器官结构完成分化的时期是
A．受精后4周 B．受精后6周C．受精后7周 D．受精后8周E．受精后12周
参考答案：D
---Do you still remember the accident?
--- Yes. Actually, I have experienced nothing more ________.
A．frighten
B．to be frightening
C．frightened
D．frightening
开水白菜在焯水时一定要焯透，必须达到八成熟。( )
