()是焊接紫铜时，母材和填充金属难以熔合的原因。
A、紫铜导电好D
暂无解析
下列哪项不是胎盘剥离征象
新生儿出生后()Apgar评分对估计预后很有意义。
PartIVTranslation
Thecaptainrealizedthatthementriedtodeceivehimsohemadethemworkveryhardfortherestofthevoyage.(PassageOne)
PartIVTranslation
Bymakingvehicleslighterinweightaluminumhasgreatlyreducedtheamountoffuelneededtomovethem,(PassageTwo)
PartIVTranslation：
Almost30millionAmericansweightatleast20percentmorethantheiridealweight.Infact,theUnitedStateisthemostoverweightcountryinthewild.(PassageThree)
