today the team came back and said, okay, we have your answers. we do know that three of them cannot be turned off manually. one of them can. so, they're starting to get answers to some of these very technical issues. christine? >> all right. thank you so much, pauline chiou, for that this morning in beijing. >> one of the biggest obstacles in the search for flight 370 for the last three weeks has been the weather of the coast of australia. the question is, what's coming next? will the weather help or hurt? our indra petersons is here with that. good morning, indra. >> good morning. >> good morning. so key to know what's going on in the air as well, of course on the water itself. i want to take you back to the basics and talk about the pinger. a lot of people still confused. we're talking about the commercial aircraft pinger. let's talk about how they're hoping to find this. you're going to see a boat go by and it's going to look for the pinger at the right frequency, kind of acts like a microphone, searching at that exact frequency, going by just at several knots. notice that locator only goes up to about 20,000 feet. this is key because we need to talk about what that terrain is like underneath the water there, and not all of that terrain is