铅套管使用前,铅套管的内外壁距两端部分均要刮净,其内壁的刮净长度()mm。
A.10
B.20
C.10~20
D.25
参考答案:D
在左侧卧位时腹痛可减轻,这种情况常见于下列哪种疾病()
A.胃粘膜脱垂
B.胰腺癌
C.急性胆囊炎
D.急性胃炎
E.阑尾炎
A manufacturing project has a schedule performance index(SPI)of 0.89 and a cost performance index(CPI)of 0.91.Generally,what is the BEST explanation for why this occurred ?()
A.The scope was change
B.A supplier went out of business and a new one needed to be foun
C.Additional equipment needed to be purchase
D.A critical path activity took longer and needed more labor hours to complet