You will spend hours at the gym training your body, but do you ever think about training your brain? Here are four ways to keep your brain mentally   active and healthy. Play games Your brain is a muscle just like the ones in the rest of your body. If you don't use it, you will lose it. For example, doing a crossword puzzle   once a day is a good way to give the brain the exercise it needs. This kind of puzzle is good at training different areas of the brain. But remember that when doing this puzzle, you should gradually increase the complexity  ; otherwise, it will become repetitive   and stop being mentally challenging. Talk aloud Although it might sound strange to you, talking aloud is a great way to _ your memory. A good exercise to try is counting to 99 in threes as fast as you can. Be a team leader If you find you can do your work very easily, you should find a new task. It is important that your job should be mentally challenging. Complex jobs are often more challenging and make the brain work a little harder. Learn a language A study found that, compared with those who could speak only one language, the people who could speak two languages had a slower rate of cognitive   decrease. Learning a new language is very challenging and it makes sure that different areas of the brain have their lights on. We should gradually increase the complexity when doing crossword puzzles because   _  .
if we don't use our brain, we will lose it we should make our brain face different challenges our brain is a muscle like other parts in our bodies these puzzles can work on different areas of the brain
Question: You will spend hours at the gym training your body, but do you ever think about training your brain? Here are four ways to keep your brain mentally   active and healthy. Play games Your brain is a muscle just like the ones in the rest of your body. If you don't use it, you will lose it. For example, doing a crossword puzzle   once a day is a good way to give the brain the exercise it needs. This kind of puzzle is good at training different areas of the brain. But remember that when doing this puzzle, you should gradually increase the complexity  ; otherwise, it will become repetitive   and stop being mentally challenging. Talk aloud Although it might sound strange to you, talking aloud is a great way to _ your memory. A good exercise to try is counting to 99 in threes as fast as you can. Be a team leader If you find you can do your work very easily, you should find a new task. It is important that your job should be mentally challenging. Complex jobs are often more challenging and make the brain work a little harder. Learn a language A study found that, compared with those who could speak only one language, the people who could speak two languages had a slower rate of cognitive   decrease. Learning a new language is very challenging and it makes sure that different areas of the brain have their lights on. We should gradually increase the complexity when doing crossword puzzles because   _  .
A. if we don't use our brain, we will lose it
B. we should make our brain face different challenges
C. our brain is a muscle like other parts in our bodies
D. these puzzles can work on different areas of the brain
Answer: