题目内容：

In a six-week study, experts found people who played online games designed to improve their cognitive(认知的) skills didn't get any smarter.

More than 8,600 people aged 18 to 60 were asked to play online brain games designed by the researchers to improve their memory, reasoning and other skills for at least 10 minutes a day, three times a week. They were compared to more than 2,700 people who didn't play any brain games, but spent a similar amount of time surfing the Internet and answering general knowledge questions. All participants were given a sort of I.Q test before and after the experiment.

Researchers said the people who did the brain training didn't do any better on the test after six weeks than people who had simply been on the Internet. On some sections of the test, the people who surfed the Net scored higher than those playing the games.

"If you're (playing these games) because they're fun, that's absolutely fine," said Adrian Owen, the study's lead author. "But if you're expecting (these games) to improve your I.Q., our data suggests this isn't the case," he said during a press briefing on Tuesday.

One maker of brain games said the company's games have been proven to boost brain power.

"Their conclusion would be like saying, 'I cannot run a mile in under 4 minutes and therefore it is impossible to do so," Aldrich said in a statement.

"There is precious little evidence to suggest the skills used in these games transfer to the real world," said Art Kramer, who was not linked to the study and has no ties to any companies that make brain training games.

Instead of playing brain games, Kramer said people would be better off getting some exercise. He said physical activity can spark(激发) new connections between nerves and produce new brain cells. "Fitness changes the building blocks of the brain's structure," he said.

1.. It can be inferred that the online brain games mentioned in the text are_____________.

A. costly     B. unreliable      C. illegal    D. effective

2.. Which of the following statements is true about the experiment in the second paragraph?

   A. The experiment lasted for a week.

B. Age didn’t affect the result of the research.

C. Every person played online brain games three times a day.

D. People who didn’t play online brain games did better in I.Q test

3.. What can we learn from the text?

   A. Playing games which are fun can improve your I.Q.

B. There is a lot of evidence to suggest skills can transfer to the real world.

   C. Do physical activity can boost your brain power.

D. Playing online games can spark new brain cells

4.The underlined sentence suggests that ___________.

   A. The research was not linked to the study  

B. Those playing the games can score higher in the test

C. playing the games can spark new connections between nerves

D. This isn’t the case that these games can improve your I.Q.