人机工程学的研究对象是（）。 ["人和机器设备","人、机器和环境的相互作用关系","人、机器和环境","人与广义环境的相互作用关系"]
反滤层中各层滤料的粒径顺渗流方向布臵应由粗到细。
咽颅
患者，男性，35岁，因车祸急诊送手术室。查体：R35/min，BP76/5OmmHg，神志淡漠，明显呼吸困难，右肺呼吸音低，右下胸骨擦感，胸壁有一伤口，有血液及气泡溢出。腹肌紧张，明显压痛、反跳痛，肠鸣音减弱。左下腹穿刺抽出不凝血。首要处理是（） ["输血、输液及止血","胸腔穿刺抽血","胸腔闭式引流","给氧","封闭胸壁伤口"]
You share your computer with other users. You install a new Microsoft add-on to view videos on the computer. You discover that this add-on conflicts with existing add-ons that other users frequently require. You need to ensure that you are able to view videos without affecting other users. What should you do?（） ["A","B","C","D"]
系统训练与周期安排原则
