2014英语四级听力练习慢速4.19(1)_大学英语听力

2014英语四级听力练习慢速4.19(1)

　　Paul Nelson is with Phoenix International, the company that makes the pinger locators.

　　You might hear that tiny little chirp and say, Did you hear something? And then we will listen more intently and try to fine-tune it.

　　Fine-tuning it means turning the boat and changing position of the locator. The operation takes eight hours. Search time is limited. The energy source for the black box does not last forever. The battery power is guaranteed to last 30 days but can go longer. However, the sound will disappear at some point.

　　Jim Gibson is also with Phoenix International ?. The advertised shelf life for the pinger when its in the water is 30 days. We have individuals that have been out on operations that have heard the pinger well beyond 45 days.

　　Once suspected wreckage is identified, a robotic device is deployed to the area. The small device, called Remora, is controlled from the larger ship. It carries a camera that records video of the area. Remora also has a very strong mechanical arm. It picks up wreckage and puts it into a box. The box is then pulled to the surface.

　　Remora helped in the recovery of Air France Flight 447 which crashed into the Atlantic Ocean in . The aircraft was lost for five days. Remora recovered the planes engines, computers, and black box.

　　The process of finding wreckage in the ocean takes time and patience. Conditions are difficult. It is often difficult to see. The weather can cause problems too. And, the pressure is extreme in deep water.