骶髂关节功能障碍的最常见症状为()

A．下肢无力

B．大腿麻木

C．骶髂关节压痛

D．疼痛放射至腹股沟

E．步行时疼痛

Housing construction materials give off distinctive sounds when exposed to high temperatures. Acoustic sensors accurately detect such sounds and fire alarms incorporating acoustic sensors can provide an early warning of house fires, allowing inhabitants to escape before being overcome by smoke. Since smoke inhalation is the most common cause of fatalities in house fires, mandating acoustic-sensor-based alarms instead of smoke detectors will eliminate house fire as a major cause of death.
Which of the following, if true, most weakens the argument given

A．The present high cost of acoustic-sensor-based alarm systems will decline if their use becomes widespread.

B．When fully ignited, many materials used in housing construction give off sounds that are audible even from several hundred yards away.

C．Many fires begin in cushions or in mattresses, producing large amounts of smoke without giving off any sounds.

D．Two or more acoustic-sensor-based alarms would be needed to provide adequate protection in some larger houses.

E．(E) Smoke detectors have been responsible for saving many lives since their use became widespread.