干扰电疗法差频为（） A.0～1000Hz B.0～100Hz C.50～200Hz

隐性颅裂()
显性颅裂()

A．颅骨缺损

B．颅腔内容物膨出

C．两者均有

D．两者均无

A 15-year-old girl with anorexia refuses to eat in a mental health unit. Which of the following statements is the best response from the nurse

A．"Why do you think you're fat You're underweight. Here--look in the mirror. "

B．"You really look terrible at this weight. I hope you'll eat. "

C．"You don't have to eat. It's your choice. "

D．"I hope you'll eat your food by mouth. Tube feedings and IV lines can be uncomfortable. "

若结构为非导电的屋顶时，则采用避雷带保护，该避雷带的网格为8～10m，每隔( )设引下线接地。

A．15～25m

B．20～30m

C．10～20m

D．15～20m

如图所示，车内绳AB与绳BC拴住一小球，BC水平，车由原来的静止状态变为向右加速直线运动，小球仍处于图中所示的位置，则(　　)

A．AB绳、BC绳拉力都变大

B．AB绳拉力变大，BC绳拉力变小

C．AB绳拉力变大，BC绳拉力不变

D．AB绳拉力不变，BC绳拉力变大

管片进场作业控制要点有哪些？