3．Why are people interested in eating raw foods or whole foods？One reason is that eating these types of food reduces the risk of acid accumulation in your body．
Raw and whole foods are usually digested more efficiently than cooked and refined foods．When we cook foods，we destroy the natural enzymes（酶）that are part of the food in its raw form．These enzymes were intended by nature to help us digest the food．When we consume food without these natural enzymes，our bodies either digest the food improperly or allow too many nutrients to be absorbed into the bloodstream．In both instances，the result is obesity．When too many nutrients are absorbed at once，the body grows fat．Improperly digested food moves slowly through the digestive tract，where it becomes increasingly acidic （酸性的）．To protect its vital organs from this acidic waste，the body changes the acid into fat and stores it safely away from the organs．
Processed foods contain chemical elements，which might confuse the appetite mechanism that tells us when we've had enough to eat； as a result，people often overeat．Processed foods also upset the digestive cycle．The body will either identify these foods as allergens and then store them safely away from the organs as fat，or the remains of undigested food will become acidic and enter the bloodstream as acid waste，which will stick to the blood vessel walls and block the passage of vital oxygen and nutrients heading for the body's cells．The body's metabolism（新陳代謝） becomes inactive，and then result is weight gain and obesity．
The accumulation of acid in the digestive tract makes digestion increasingly inefficient．When that happens，even healthy foods can become acidic and the food allergies will become more common．
To stop this vicious（惡性的） circle in its tracks，people need to consume food and supplements that will neutralize （使…中和）the acid already accumulated in body．Eating the right types of raw and whole foods can help．It's also important to restore your enzyme balance．You need to identify and avoid the foods that cause acid accumulation and consume the foods that increase enzyme production．If you truly want to change and help your body heal itself，you need to take an active approach．
27．What is the main purpose of this passage？B
A．To tell the differences between raw and processed foods．
B．To advocate eating more raw and whole foods．
C．To inform people of the harm of processed foods．
D．To warn people of the problem of obesity．
28．It can be inferred from Para.2thatD．
A．it is essential for people to protect their vital organs
B．giving up cooked and refined foods is a new lifestyle
C．we'd better be cautious about raw and whole foods
D．foods with natural enzymes help people keep fit
29．Processed foods are unhealthy because theyB．
A．destroy body's cells
B．may lead to obesity
C．are difficult to digest
D．stop body's metabolism
30．What is likely to be talked about following the last paragraph？A
A．Suitable types of raw and whole foods．
B．Different causes of acid accumulation．
C．Correct ways to cook raw foods．
D．Active approaches to avoid acid．
31．What can we learn from the text？C
A．Processed foods are good for our appetite mechanism．
B．The accumulation of acid in the digestive tract makes digestion more effective．
C．Eating the right types of raw and whole foods does good to our body．
D．Processed foods also comfort the digestive tract．
分析 本文主要講述了天然健康食品對人體的好處，可以減少體內酸的積累，可以讓我們的消化更為有效健康．所以倡導人們多食用這樣的天然健康食品．
解答 27．B推理判斷題，根據文章第一段的內容可知，吃天然健康食品可以減少體內酸的積累，可以讓我們的消化更為有效健康．說明本文的目的在于建議人們多吃這樣的天然健康食品，故選B．
28．D 推理判斷題，根據文章第二段的"Raw and whole foods are usually digested more efficiently thancooked and refined foods．When we cook foods，we destroy the natural enzymes （酶） thatare part of the food in its raw form．"可知，天然健康食品通常比煮熟的和精制的食物更有效地消化．當我們烹調食物時，我們破壞了作為食物的一部分的天然酶．含有天然酶的食物可以幫助我們更高效地消化食物．幫助我們保持健康．故選D．
29．B 細節理解題．根據文章第二段的"When we consume food without these natural enzymes，our bodieseither digest the food improperly or allow too many nutrients to be absorbedinto the bloodstream．In both instances，the result is obesity．"可知，當我們食用沒有這些天然酶的食物時，我們的身體要么不適當地消化食物，要么吸收太多的營養物質進入血液，在這兩種情況下，結果就是肥胖．所以這些處理過的食物會導致人們發胖．故選B．
30．A 細節理解題，本文主要講述了這些天然健康食品的好處，接下來就應該是向我們介紹那些適合人們食用的食品．故選A．
31．C 推理判斷題，通過全篇的閱讀可以看出：本文主要講述的是食用天然健康食品對我們身體的好處．故選C．
點評 本文是健康環保類閱讀，主要考查細節理解題和推理判斷題．在做細節理解題時，首先根據題目要求迅速在文章里找出相應的段落、句子或短語．認真比較選項和文中細節的區別，在做推理判斷題時不要以個人的主觀想象代替文章的事實，要根據文章事實進行合乎邏輯的推理判斷．
