If you build a campfire, you start with a large stack of sticks and logs. As the fire burns, the stack slowly shrinks. By the end of the evening, all that is left is a small pile of ashes. What happened to the matter that you started with? Was it destroyed by the flames? It may seem that way. What do you think happened? The truth is that the same amount of matter still exists. The wood changed not only to ashes, but also to carbon dioxide, water vapor, and other gases. The gases floated off into the air, leaving behind just the ashes. Although matter was changed, it was not created or destroyed. Because the same amount of matter still exists, we can say that matter is conserved. You may wonder how it can be conserved if something is now missing? Assume you had measured the mass of the wood before you burned it. Assume you had also trapped the gases released by the burning wood and measured their mass and the mass of the ashes. What would you find? The ashes and gases combined have the same mass as the wood you started with. This example illustrates the law of conservation of mass.

Question: "What happened to the matter changed to when burning a fire?"

Response: "It was destroyed"
OPTIONS:
- no
- yes

A: no

Dr. Alex Cross is a psychiatrist and police lieutenant who lives in Detroit with his wife , Maria , their children , Damon and Janelle , and his grandmother , Nana Mama . Upon learning that Maria is pregnant with their third child , Cross considers accepting a job as an FBI profiler , but fears Maria's reaction , as it 'd require them to relocate to Washington , D.C. Meanwhile , a man called Picasso attends to an illegal underground Mixed Martial Arts fighting ring , where he flirts with businesswoman Fan Yau . After brutally beating his opponent , Picasso is invited to Fan Yau's house , where he sedates her while they 're having sex , tortures and kills her . Police Captain Richard Brookwell calls Cross and his partner , Tommy Kane , to the crime scene . On the way there , Cross tells Kane about Maria's pregnancy and the the FBI's offer , and Kane reveals that he is secretly dating their colleague , Monica Ashe . Cross deduces that Picasso is a professional assassin , and finds a sketch made behind by Picasso , revealing that his next target is businessman Erich Nunemarcher . Cross , Kane and Ashe go to Nunemarcher's office , but Nunemarcher ignores their claims . Picasso manages to enter the building , but is prevented from killing Nunemarcher by Cross , and escapes after being shot by Kane . Cross analyzes a drop of Picasso's blood and learns that he is a psychotic former member of the Special Forces and that his real target is billionaire CEO Leon Mercier . Cross informs Mercier that Picasso might be trying to kill him .

Question: "How many couples are linked romantically in the story?"

Response: "2 couples: Alex & Maria, Damon & Janelle"
OPTIONS:
- no
- yes

A: no

Plants also detect the daily cycle of light and darkness. Do you know how plants respond to these changes? Some plants open their leaves during the day. It is during these hours the plant can collect sunlight. At night, the plant closes its leaves to prevent water loss. Many plants respond to the change in the length of the day. As days grow shorter, some plants respond by going dormant. Dormant is when a plant suspends its growth. It does this in order to survive. Shorter days signal the coming of winter. Winter in most areas means extreme cold. It is also very dry in the winter months. As winter approaches, some plants respond by their leaves changing color. After the change in color, they fall off. This dormancy period helps trees. It allows them to survive the cold and dry winter. Plants only want to grow when conditions are right.

Question: "What are the right conditions for plants to grow in?"

Response: "Somewhat cold and dry"
OPTIONS:
- no
- yes

A:
no