特发性血小板减少性紫癜最主要的发病机制是()
A.凝血功能异常
B.自身免疫引起
C.血小板功能异常
D.脾破坏血小板增加
E.微血管的变态反应性炎症
参考答案:B
On the coast _______ with an old temple _______ back to Ming Dynasty.
A.does a village stand; dated
B.stands a village; dating
C.a village is standing; dates
D.a village stands; to date
室内燃气管道阀门宜采用()。
A.切断阀
B.止回阀
C.球阀
D.闸阀