北魏相州以制造军刀著称，反映了冶炼技术的进步，下列叙述对此阐释正确的是

A．把冶炼技术用于军械制造，反映了北方战乱频繁

B．北魏相州自古就是冶铁的传统中心

C．全国的军械主要是靠相州提供的

D．反映了手工业的冶炼水平具有世界先进意义

Before a transesophageal echocardiogram, a client is given an oral topical anesthetic spray. Upon return from the procedure, the nurse observes that the client has no active gag reflex. In response, the nurse should

A．insert an oral airway.

B．withhold food and fluids.

C．position the client on his side.

D．introduce a nasogastric (NG) tube.