奶牛慢性子宫内膜炎,表现为()。
A.有明显的全身症状
B.自阴门流出混浊渗出物
C.妊娠后期流产
D.卧地时自阴门流出多量渗出物
参考答案:B, D
Only after her mother came to help her for the first few months ______ to begin her project.
A.did she allow
B.had she allowed
C.was she allowed
D.is she allowed
在802.45.4定义中的器件有()
A.FFD
B.FPD
C.RFD