Until just a few years ago，we doctors believed that the brain stopped making new neural(神经系统的)connections (meaning that your memory began to get worse)when the body stopped developing，usually in your early 20s. And we knew that，like any other body part，neurons weaken as we age. Loss of brain function due to neural breakdown was assumed to be a normal，unavoidable part of aging.
It turns out that we were wrong. In the past few years，it has been discovered that you can，in fact，make new neurons starting in your 20s and continuing well into old age. You can literally rewire the brain with new parts as the older parts wear out. How？Simple：Keep learning. Just as your body can pack on and condition new muscle，your brain can rebuild used-up neurons.
How strong is the evidence for this？Strong enough that a $200 million industry devoted to brain boosting software (products like Brain Age，MindFit，and Lumosity that supposedly improve your memory function)has sprung up out of nowhere. All“mental fitness”means are keeping your memory intact(everything from phone numbers to how to throw a football)．So what can you do to stay smart?
Keep blood pressure down. People with high blood pressure are more likely to develop cognitive impairment later in life.
Eat more vitamins. Like E(in nuts and sunflower seeds)，B6 and B12(beef，tuna)，and folic acid(leafy greens，citrus，berries)，which help keep your brain’s chemistry in balance.
Exercise your brain. This is the best way to rebuild and strengthen those precious neurons. Learn to play chess or the guitar. When you’re at a stoplight，try to recall the starting lineup of the 1983 Celtics. See a movie that doesn’t feature Ben Stiller. Or read，like，a book.
Title：How to keep the ________smart？

Previous ____	The brain no longer makes new neural connections once the ________ of one’s body has stopped.
New ________	●New neurons continue to occur even in one’s old age. ●________contributes to the development of the new parts of your brain. ●Many products which claim to improve your brain function appear in the _________.
_______	●Keep yourself away from _________blood pressure. ●_________in more vitamins for the needs of your brain. ●_______your brain as much as you can.