Refer to the exhibit. The Hamilton Hair Emporium was having difficulty hearing during conference calls. This configuration adjustment was made, and now the company is experiencing sound distortion. What is the cause?（） The gain functionality applies to outbound audio packets. Distortion is created when an external participant causes echo. 。 The distortion is unrelated to the gain functionality. Rather, it is a result of the company trying to maintain too many conference calls at one time. 。 This functionality cannot discriminate between a local VoIP source that requires volume gain and a CO-powered PSTN source that does not require volume gain. 。 This functionality cannot discriminate between a remote VoIP or Foreign Exchange Office source that requires volume gain, and a remote VoIP or IP phone that does not require volume gain.&e。
焊接常用的低碳钢有（）。 Q235。 20g。 16Mn。 20R。
患者，女性，54岁。突发上腹部剧烈疼痛，2h后扩散至全腹部，持续性疼痛，无放射痛，伴恶心呕吐。体格检查：体温38.9℃，呼吸急促26/min，脉搏85/min，血压120/75mmHg，腹部平坦，全腹压痛、反跳痛、腹肌紧张，以上腹部和中上腹部最为明显，肝脾浊音界不清楚，肠鸣音减弱该患者发生的情况是（） 原发性腹膜炎。 继发性腹膜炎。 休克早期。 胃炎加重。 急性化脓性阑尾炎。
男性，30岁，因车祸撞伤腹部，诉腹痛，伴恶心、呕吐、呕吐物量少，X线透视可见隔下游离气体，拟诊为胃肠道穿孔。手术治疗，术中应做到（） 清理腹腔。 吸净脓液。 尽可能去除原发病灶。 安置腹腔引流。 以上均是。
我国第一部以分析汉字形体构造为主要内容的字书是（）。
客户关系的发展阶段可以划分为（）。
