确定肺结核是否为传染源的最主要依据是（）。

A．血沉检查

B．X线检查

C．痰结核菌检查

D．结核菌素试验

E．血结核抗体检查

refers to carrier picking up merchandise from the shipper's warehouse and delivering it to the consignee's warehouse.（）

A．Through transport

B．Combined transport

C．Container transport

D．Door-to-door