题目内容：

根据短文内容，从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

A strong memory depends on the health and vitality （活力） of your brain. They say that you can’t teach an old dog new tricks, but when it comes to the brain, scientists have discovered that this old saying simply isn’t true.   1.

Give your brain a workout. Memory, like muscular strength, requires you to “use it or lose it”. The more you work out your brain, the better you’ll be able to process and remember information.   2.  

Don’t skip the physical exercise. While mental exercise is important for brain health, that doesn’t mean you never need to break a sweat. Physical exercise helps your brain stay sharp. It increases oxygen to your brain and reduces the risk for disorders that lead to memory loss.

Get enough sleep. There is a big difference between the amount of sleep you can get by on and the amount you need to function at your best.   3.

Keep stress in check. Stress is one of the brain’s worst enemies. Over time, stress destroys brain cells. Studies have also linked stress to memory loss.

Have a laugh.   4.  That holds true for the brain and the memory, as well as the body. Unlike emotional responses, which are limited to specific areas of the brain, laughter engages multiple regions across the whole brain.

5.   Just as the body needs fuel, so does the brain. You probably already know that a diet based on fruits, vegetables, whole grains, “healthy” fats and lean protein will provide lots of health benefits, but such a diet can also improve memory. For brain health, though, it’s not just what you eat—it’s also what you don’t eat.

A. Eat a brain-boosting diet.

B. Play games with memory.

C. Laughter is the best medicine.

D. But oversleeping is not good for your brain.

E. Even skipping a few hours makes a difference!

F. You have to shake things up from time to time!

G. The human brain has an astonishing ability to adapt and change.