The following are stories and questions about them. Each story is followed by a question and answer to a given question.

Story: (CNN) -- It's been more than three weeks since militants from the dreaded Boko Haram terrorist group dragged 276 girls out of their beds at a boarding school in northern Nigeria, and still no one knows where the girls are. International assistance has begun to flow into Nigeria, whose president has vowed to end the terror threat plaguing his country. 

Here's what you need to know to get caught up: 

Where are the girls? 

It's anyone's guess. Boko Haram's leader, Abubakar Shekau, said in a video that he was going to sell them into slavery, but it's unknown whether he has. Pentagon spokesman U.S. Navy Rear Adm. John Kirby and other officials have said they believe the girls may have been separated into smaller groups, making the task of finding them inordinately more difficult. Gordon Brown, a former UK prime minister and the U.N.'s special envoy for global education, speculated that the girls may have been moved into neighboring countries. "The search must be in Niger, Cameroon and Chad, to see if we can find information," he said. 

What's being done to find them? 

Nigeria hasn't given a lot of information about its efforts other than to say that its soldiers have been out in the field, looking for the girls. Nigerian police offered a $310,000 reward, but there's no evidence that has turned up any leads. The United States and Britain have sent advisers to help the Nigerian government find the girls, stage rescue missions and help in the larger fight to defeat Boko Haram. 

Question: How many girls?
Answer:276

Question: Who took them?
Answer:Boko Haram

Question: Where were they before they were taken?
Answer:a boarding school in northern Nigeria

Question: Who is helping?
Answer:the United States and Britain

Question: Who is in charge of hostages?
Answer:unknown

Question: Where are they searching?
Answer:Niger, Cameroon and Chad

Question: What did he claim he would do to the hostages?
Answer:sell them into slavery

Question: Has he done this?
Answer:it's unknown

Question: Has there been any clues to there whereabouts?
Answer:no

Question: Is there an incentive to locate them?
Answer:yes

Question: What is it?
Answer:a $310,000 reward

Question: Who needs to be defeated?
Answer:Boko Haram

Question: Why is it difficult to find them?
Answer:the girls may have been seaprated

Question: Who is speaking about this?
Answer:Pentagon spokesman U.S. Navy Rear Adm. John Kirby

Question: Is there another person?
Answer:other officials

Question: Who is advising?
Answer:The United States and Britain have sent advisers

Question: Who is fighting terror?
Answer:the Nigerian government

Question: Who put out a video?
Answer:Abubakar Shekau

Question: What role does he have?
Answer:he's Boko Haram's leader

Question: How long have they been missing?
Answer:3 weeks

Question: What is Boko haram?
Answer:a terrorist group

Question: Where they taken in the daytime?
Answer:no

Question: Where are they thought to be now?
Answer:
It's anyone's guess