合金钢管上要有材质标记。
参考答案：对
When is breakfast? [ ]
A. Breakfast is at 7: 00 in the morning.
B. Breakfast is at 8: 00 in the morning.
Charcot三联征出现在( )
A．急性梗阻性化脓性胆管炎B．急性化脓性胆囊炎C．绞窄性小肠梗阻D．急性出血、坏死性胰腺炎E．急性化脓性阑尾炎
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