煤气管道冷凝液水封槽一般水封高度≥（） ["2米","1米","1.2米","1.6米"]
The longer the ignition delay period occurs in a diesel engine, the （）. ["less fuel will enter the cylinder","lower will be cylinder compression temperatures","more complete will be fuel combustion","more rapid will be the rise in combustion pressure"]
影响培训需求的因素有常规因素和非常规因素。
对于一个液化气球罐来说，当球罐收发液化石油气时，该系统就为（）。 ["孤立系统","闭口系统","绝热系统","开口系统"]
将数据组成适合于正确传输的帧形式，提供可靠的信息传送机制是（）。 ["物理层","链路层","传输层","会话层"]
简述个人消费者的购买行为类型的种类。
