哪类肺癌在早期就发生淋巴转移()
A.鳞癌
B.腺癌
C.大细胞未分化癌
D.小细胞未分化癌
E.细支气管肺泡癌
参考答案:D
预制钢筋混凝土柱插入杯形基础,并用细石混凝土浇筑,这种约束称为______。
A.柔性约束
B.光滑接触面约束
C.铰支座约束
D.固定端支座约束
On a ship,when may a work vest be substituted for a required life preserver?()
A.To replace a damaged life preserver
B.For use during fire drills
C.For use during boat drills
D.At no time