We're starting in the nation of Turkey where the leaders

20 countries have gathered for the annual G20 Summit.

Usually, it focuses on global economic growth,

but the recent terrorist attacks in Paris, France

are dominating discussions at the G20.

US President, Barrack Obama, held a press conference yesterday.

He spent a good part of it defending US strategy for fighting ISIS,

as criticism increases that America isn't doing enough

to defeat the terrorist group.

There have been a few who suggested that we should put

large numbers of US troops on the ground.

It is not just my view, but the view of my closest military

and civilian advisers that that would be a mistake.

The president plans to keep the current US strategy in place,

which partly involves air strikes on ISIS targets

and helping local groups fight ISIS.

The Obama administration also says it's sticking with plans

to accept 10, 000 Syrian refugees in the US next year.

Yesterday, at least 19 US states announced they were

against allowing Syrian refugees to resettle there.

18 of them are led by Republican governors.

One is by a democrat.

And at least five states said they'd accept refugees.

All of them led by Democratic governors.

Part of the reason for the controversy is that French authorities reported

at least one of the terrorist attackers had entered France

with the flood of refugees from Syria,

and six of the terrorists had reportedly spent time in Syria.

The US State Department says it has a process that

allows for the safer settlement of Syrian refugees.

The director of the Central Intelligence Agency says

the Paris attacks probably weren't a one- off event.

So, security's being increased across Europe.

French President Francois Hollande announced 5, 000 positions

would be added to his country's paramilitary police force.

Seven attackers were killed in the Paris assault,

but the Islamic terrorist group ISIS,

which claimed responsibility says eight attackers were involved.

So, the search for suspects continues.

The US and France say they are increasing the ways they share intelligence.

When we're talking about terror investigations across 50 states,

hundreds or thousands of investigations simultaneously,

you can't go into a single investigation as a one- off every time.

It's not a new process every time you open a case.

There are simple ways to consider how to break down a case.

So, let's go through six or eight of them. You wanna talk about money,

where the money for the group is coming from.

You wanna talk about travel, whether the individuals in the group

have gone someplace to receive training.

You wanna know who the conspirators are.

You wanna know who's at the core of this spiderweb of conspiracy.

You wanna know what we call facilitators. Who, for example,

provided documentation? Who provided assistance to travel overseas?

You want to know about documents, passports, drivers license.

You wanna know the critical question, do they have access to weapons and explosives?

When you're looking at a case like this,

you have to understand these initially to break down the case

to determine its complexity.

Among all these, there are two or three that I would focus on

to ensure that you own the case.

The first and most significant,

do I have one spider in the spiderweb or ten?

Second thing you want to focus on,

do these guys have the capability to do something tonight

in America that threatens a woman or child or a family?

Last and most interesting, travel.

In my experience, as soon as you see travel to a place like Yemen,

Somalia, Pakistan, Afghanistan, Syria, and Iraq.

They think in a fundamentally more sophisticated way than

somebody who has not had access to overseas training.

So, you walk in the room in the morning,

7 o'clock tomorrow morning. Don't say, hey, we've got another terror threat in New York,

or Chicago, or Los Angeles. Say, hey, we've got another case.

There is a way to break down this case so not everyone is new,

and there are some things we wanna prioritize to ensure that every time,

we can take it down clean and neat. Thank you.

The American Academy of Pediatrics says the use of antibiotics

in farm animals is threatening the children who eat meat.

How? Well, antibiotics are used to kill infections.

But there's been an increase in peoples' resistance to certain antibiotics.

Meaning the drugs aren't as effective as they used to be.

Health officials say part of the reason for this is that doctors

sometimes prescribe antibiotics when they're not necessary.

The pediatrics organization, which focuses on children's health,

says another reason for resistance is because antibiotics are overused

in farm animals. So, they're encouraging parents to buy meat that has been raised without antibiotics.

Why do some farmers use them? For one thing,

they help keep the animals healthy. And they help them gain weight,

which makes the animals more profitable for farmers.

Western France is where we begin today's Roll Call.

A warm welcome to our viewers in [ FOREIGN ].

We're glad to be part of your day at University Institute of Technology.

The western US is up next. In the city of Bend, Oregon,

don't tread on the Diamondbacks of High Desert Middle School.

And finally, to West Virginia, the Applemen are here.

Hello to everyone at Musselman High School in the community of Inwood.

We recently reported on companies that were looking to use low- orbit satellites

to bring internet access to people who don't have it.

One of the downsides we mentioned, space junk.

NASA estimates there are around 500, 000 pieces of space junk

floating around above us. Could be spacecrafts that don't work,

parts of rockets we've launched, garbage or debris from previous missions.

Scientists are concerned about this junk potentially threatening future missions

or hitting something if it falls back to Earth.

There's some speculation that it could be,

maybe a spent third stage from one of the Apollo moon missions

that's been going around in system lunar space for this many decades,

because it's in a highly elliptical orbit. And so,

that's kinda what causes it to come in so sharply.

Staying in the sky. The uses for drones, unmanned aircraft, continue to expand.

We've talked about them in the military, in search and rescue,

in getting video of hard to reach disaster areas.

How about their potential in sports? You might not need a pilot's license for this.

It really feels like nothing you can describe.

It feels like you're flying. The trick, really, is in the camera and the transmission.

The transmission of the video signal to the pilot while he's flying,

he's watching it through these goggles.

It's so immersive that your brain really thinks you're in the air frame.

Many pilots cannot fly standing up.

They have to sit down, because you literally would sway your body

to follow the motions of your air frame.

Drone racing, then, is basically you getting together with a bunch of friends,

and race these air frames together, chasing each other through very tricky courses,

and determining whose the best pilot and gets there first.

Drone racing has been just a hobby.

I think now the challenges starts where, we're really thinking that there's a sport

in drone racing. At the Drone Nationals, we had thousands of people

view the race online, and it showed us that there's huge demand

for the pilots that are still dispersed around the world

to join in and watch an event. I think, that in five years,

we will have a very vibrant and well- established drone racing sport,

and all the infrastructure to support it, as well.

Using puns, we can drone on about the plans drone up

and the skill drone upon to droniminate such a sport.

Could get pretty drone- out. But one thing that's undroneable,

it's certainly a sport for control freaks.

Teachers, we've corrected a technical issue.

You can now send us an email once again from the feedback tab

at CNNStudentNews. com. We don't accept Roll Call requests from that link,

but anything else that's on your mind, we'd love to hear about.

Have a great Tuesday.