1. (2020·温州模拟) 听材料，回答问题。

Today, I'd like to talk about electronic cigarettes.<br />Electronic cigarettes are battery-operated devices.<br />They are designed to deliver nicotine and other chemicals to users in steam, while traditional<br />cigarettes deliver nicotine in smoke by burning tobacco.<br />E-cigarettes are often promoted as safer alternatives to traditional cigarettes.<br />But little is actually known yet about the health risks of using these devices.<br />Although they do not produce tobacco smoke, e-cigarettes still contain nicotine and other<br />potentially harmful chemicals.<br />The health consequences of repeated exposure to these chemicals are not yet clear.<br />Some people believe e-cigarette products may help smokers lower nicotine addiction when<br />they are trying to quit their tobacco use.<br />However, at this point it is unclear whether e-cigarettes may be effective.<br />In addition, there is currently no regulation of the liquids that are used in e-cigarettes.<br />So there are no accepted measures to confirm their purity or safety.<br />Today I'd like to talk about electronic cigarettes.<br />Electronic cigarettes are battery-operated devices.<br />They are designed to deliver nicotine and other chemicals to users in steam, while traditional<br />cigarettes deliver nicotine in smoke by burning tobacco.<br />E-cigarettes are often promoted as safer alternatives to traditional cigarettes.<br />But little is actually known yet about the health risks of using these devices.<br />Although they do not produce tobacco smoke, e-cigarettes still contain nicotine and other<br />potentially harmful chemicals.<br />The health consequences of repeated exposure to these chemicals are not yet clear.<br />Some people believe e-cigarette products may help smokers lower nicotine addiction when<br />they are trying to quit their tobacco use.<br />However, at this point it is unclear whether e-cigarettes may be effective.<br />In addition, there is currently no regulation of the liquids that are used in e-cigarettes.<br />So there are no accepted measures to confirm their purity or safety.

1. （1） How do e-cigarettes deliver nicotine?

   A . In smoke. B . In steam. C . In liquid.
3. （2） What do we learn about e-cigarettes?

   A . They help smokers stop tobacco use. B . They are safer than traditional cigarettes. C . They contain potentially harmful chemicals.
5. （3） What's the purpose of the speaker?

   A . To warn. B . To complain. C . To advertise.