题目内容：

People who smoke could lose around one third of their daily memory, researchers say.

A study by a team at Northumbria University showed that smokers lost more of their memory when compared to non-smokers.

And the research also found that those who kicked the habit saw their ability to recollect information back to almost the same level as non-smokers.

The study involved more than seventy 18-to-25-year-olds and included a research of the university .Those who took part were asked to recall small details, such as a list of songs played at the Students’ Union and tasks completed at various points .

Smokers performed badly, remembering just 59 %of tasks. But those who had given up smoking remembered 74 %and those who had never smoked recalled 81 % of tasks.

Dr. Tom Heffernan, who leads Northumbria University’s Collaboration for Drug and Alcohol Research Group, said the findings would be useful in movements against smoking. He said, “This is the first time that a study has set out to examine whether giving up smoking has an effect on memory.”

“We already know that giving up smoking has huge health benefits (好处)for the body, but this study also shows how stopping smoking can have knock-on benefits for cognitive functions （认知）too. ’’

1.The research by Tom Heffernan’s team shows that smokers remember_____.

A. 15% less than those who have never smoked

B. 33% less than those who have given up smoking

C. 22% less than those who have never smoked

D. 22% less than those who have given up smoking

2.It can be learned from the passage that ________.

A. nobody shows any interest in research by Tom Heffernan’s team

B. nobody believes the result of the research by Tom Heffernan’s team

C. nobody will risk their health or even life to go on smoking anymore

D. nobody had done the same research as Tom Heffernan’s team before

3.According to Tom Heffernan, it is necessary for smokers to ______.

A. train their memory    B. give up smoking

C. remember small details    D. Be given more tasks

4.Which of the following can be the proper title for the passage?

A. Warning :Smokers could be more forgetful.

B. Warning: Smokers wouldn’t get back memory

C. Warning: Smoking must be harmful to health

D. Warning: Smoking might cause mental problems