今天马航报道的文稿和关键词

black boxes 黑匣子: 其实是橙色的，但是一旦要找它肯定没好事，所以叫黑匣子 submersible 潜水器: 我们的蛟龙号就是一个submersible, 原意是"可以潜水的" surveillance aircraft 侦察机: surveillance是监视的意思，最常用的是surveillance camera，监视摄像头 Equipment on board the Australian vessel Ocean Shield has picked up no trace of the signal since the weekend, when the frequency was initially detected. Time is running out to find the plane's black boxes as their locator beacons have a battery life of about a month. Angus Houston, the head of the multinational search team, says it is critical to find the sound again before using a submersible to search for wreckage. "It is a large area for a small submersible that has a very narrow field of search and of course it's literally crawling along the bottom of the ocean. So it's going to take a long, long time. That's why it's so important to try and get another transmission." Over the weekend, the Australian vessel using a towed ping locator detected signals twice, with the first one lasting for more than two hours. Houston says the signals are credible. Earlier reports said that signal detected by the vessel is at a frequency of about 33 kHz, which is different from the standard level of 37.5. Houston says the difference is within a reasonable level as the transmission level can change along with the change in pressure on the ocean floor. Four Chinese naval vessels have been searching the zone where that signal was picked up. Meanwhile, the search for any trace of the plane on the ocean's surface continued on Tuesday. An Australian surveillance aircraft spotted some new objects and images have been sent for further analysis. Up to 14 planes and 14 ships joined Tuesday's search. Australian Defense Minister David Johnston says intense search will continue in the following days. "I want to confirm that we have at least several days of intense action ahead of us. The weather out there today is reasonable and so you can be assured that we are throwing everything at this difficult, complex task in at least these next several days whilst we believe the two pingers involved are still active." Locating the black boxes quickly is critical. Once their locator beacons blink off, locating the black boxes in deep water will be an immensely difficult, if not impossible task.