若空间隔离难度较大，室分需要在其它系统馈线处增加（）来实现隔离。 A.双工器 B.滤

铰孔能提高孔的形状精度但不能提高位置精度。

胃癌最常发生的转移途径

A．直接蔓延
B．血行转移
C．种植转移
D．淋巴转移
E．沿肠管转移

清朝湖南巡抚陈宝箴在长沙成立“湖南保卫局”，这是中国历史上最早的全国性专职警察机构。( )

关于慢性化脓性中耳炎，叙述正确的是（）

A.常由金黄色葡萄球菌、铜绿假单胞菌等细菌感染引起

B.可由急性化脓性中耳炎转化而来

C.反复发作的慢性鼻窦炎，细菌可经咽鼓管逆行进入中耳腔

D.鼓膜外伤穿孔后细菌经穿孔部位进入中耳腔

E.儿童咽鼓管短、平、直，细菌更易侵入

The next time you sit down with your own family to eat, please take a moment to imagine the smell of smoke, feel it in your lungs, see the soot building up on the walls, and then come find us at the Global Alliance for Clean Cookstoves. Hearths, whatever they look like, and wherever we gather around them, where we tell our stories and pass down our values, bind families together. And the benefits from this initiative will be cleaner and safer homes, and that will, in turn, ripple out for healthier families, per communities, and more stable societies. So we are excited because we think this is actually a problem we can solve.