If you searched on "smoke" you probably found from 10,000 to 200,000 hits. Most are not relevant to your search. What other keywords could you enter to narrow the search? Perhaps you could add the following: death, disease, lung, heart. How do search engines deal with multiple keywords? Do they "AND" them or "OR" them? That is, will entering multiple words serve to expand or limit your search? The answer to this question is different from search engine to search engine. Test this on each of the search engines by searching separately on two keywords and then by entering both of them. If the multiple keyword search returns more hits than the individual words, the engine chose to assume that you wanted one OR the other. If the results are less than the individual words, the engine assumed that you wanted documents which contained both of the keywords - it assumed "AND".

AltaVista (http://www.altavista.com/)	HotBot (http://www.hotbot.com)
Lycos (http://www.lycos.com/)	Excite (http://www.excite.com)