题目内容：

There’s more evidence that what’s good for your heart is good for your head．A new study shows that people who run，swim or do other moderate intensity(中等强度的)exercise have brains that look，on average，10 years younger than the brains of couch potatoes．

“Our study showed that for older people，getting moderate intensity exercise may be protective，helping them keep their brains work better，”said Dr．Clinton Wright of the University．Of Miami，who led the study．But it’s not necessarily easy．Walking，golf，bowling and yoga didn’t count，and people need to start before they begin showing memory loss，Wright’s team reported in the journal Neurology．

The study of nearly 900 people who exercise regularly showed that 90 percent fell into the low-intensity group．These people are part of a larger group taking part in a bigger study called Northern Manhattan Study．They were asked how long and how often they exercised during the past two weeks．Five years later，they were tested for memory and thinking skills and got a brain MRI．Seven years after that，they took the memory and thinking tests again．The 10 percent who said they took part in moderate intensity exercise scored better on the tests．These included running，climbing，swimming，riding bicycles and so on．

“We found that those with moderate heavy activity had higher scores and slower decline than inactive patients when comparing the results，”the study team wrote．

Many studies have shown that exercise may not prevent Alzheimer’s but may delay it．The findings fit in with a study that found two years of exercising，eating healthier food and brain training can promote people’s memory function．

1.According to the study，moderate heavy exercise________.

A．makes people’s heart better than their heads

B．helps people keep a younger brain

C．makes people ten years younger

D．makes people look like potatoes

2.What’s true about the study?

A．Most people surveyed took low-intensity exercise．

B．Only 900 people took part in the bigger study．

C．High-intensity exercise is better．

D．Ten people scored best on the test．

3.How did the study team come to the conclusion?

A．By observing people exercise．

B．By using examples．

C．By making a comparison．

D．By doing a brain MRI．

4.What’s the best title for this passage?

A．How to keep healthy

B．Ways to make your brain work better

C．To exercise or not

D．Moderate exercise keeps your brain younger