Thus，though smoking did not account for all of the decreased mental functioning observed among the alcohol abusers，it did seem to account for some of the effects，the report indicates.

　　[语篇解读]　你知道吗？抽烟使智商和思维能力下降。

1．What is the passage mainly about?

A．Cigarette smoking contributes to decreased IQ and thinking.

B．Alcohol abuse is to blame for the poorer mental function.

C．Most of the alcoholics are also heavy smokers.

D．Non-smokers mostly have higher IQ scores.

解析：主旨大意题。由第一、二段及综合全文信息可知，抽烟使智商和思维能力下降。

答案：A

2．The underlined sentence "Chronic smoking，however，is known to have the opposite effect." in Paragraph 3 implies ________.

A．chronic smoking can improve mental functioning

B．chronic smoking has an immediate influence on

mental functioning

C．chronic smoking has side effects on mental

functioning improvement

D．chronic smokers feel quicker and focused

after smoking

解析：句意猜测题。本句说明抽烟对智商和思维能力有负影响。

答案：C

3．From the passage we can learn that ________.

A．cigarette smoking is not related to reasoning

B．nicotine exposure can improve mental functioning

temporarily

C．the long-term effects of nicotine cause alcoholics

D．men with lower scores on the LAPS have lower IQ scores