« on: October 17, 2007, 01:34:06 AM »
1. Smokers of pipes or cigars run a distinctly lower risk to their health than do cigarette smokers. However, whereas cigarette smokers who quit smoking altogether sharply reduce their risk of smoking-related health problems, those who give up cigarettes and take up pipes or cigars remain in as much danger as before.
Question: Which of the following, if ture, offers the best prospects for an explaination of why the two changes in smoking habits do not both result in reduced health risks?
Answer: People who swtich from cigarette smoking to smoking pipes or cigars inhale smoke in a way that those who have never smoked cigarettes do not.
( I do not understand how inhaling smoking in a different way solves the discrepancy here).
2. Each year, an official estimate of the stock of cod in the Grand Bank is announced. This estimate is obtained by averaginf two separate estimates of how many cod are available, one based on the number of the cod caught by research vessels during a once-yearly sampling of the area and the other on the average numbers of tons of cod caught by various commercial vessels per unit of fishing effort expended there in the past year- a unit of fishing effort being one kilometer of net set out in the water for one hour. In previous decades, the two esimates usually agreed closely. However, for the last decade the estimate based on commercial tonnage has been increasing markedly, by about the same amount as the sampling-based estimate has been decreasing.
Which of the following, most helps to account for the growing discrepancy between the estimate based on commercial tonnage and the research-based estimate?
Answer: Improvements in technology over the last 10 years have allowed commercial fishing vessels to locate and catch large schools of cod more easily.
Thank you guys!