劉文勇GRE寫作Argument題庫 Day 40

Day 40 Milk and dairy products are rich in vitamin D and calcium—substances essential for building and maintaining bones

Milk and dairy products are rich in vitamin D and calcium— substances essential for building and maintaining bones. Many people therefore say that a diet rich in dairy products can help prevent osteoporosis, a disease that is linked to both environmental and genetic factors and that causes the bones to weaken significantly with age. But a long-term study of a large number of people found that those who consistently consumed dairy products throughout the years of the study have a higher rate of bone fractures than any other participants in the study. Since bone fractures are symptomatic of osteoporosis, this study result shows that a diet rich in dairy products may actually increase, rather than decrease, the risk of osteoporosis.

Write a response in which you discuss what specific evidence is needed to evaluate the argument and explain how the evidence would weaken or strengthen the argument.

五問：

（1）“this study result shows that a diet rich in dairy products may actually increase, rather than decrease, the risk of osteoporosis”是結(jié)論，其余部分是事實，值得反駁嗎？

（2）同學們應該注意到：本文使用了一項調(diào)查研究作為主要論據(jù)，那么肯定應當對該論據(jù)的有效性進行駁斥。盡管我們經(jīng)常對一項研究進行的時間長短以及所選樣本的數(shù)量進行反駁，但是在本段中，這兩點值得反駁嗎？（這兩點在原文中都已經(jīng)被額外地強化，繼續(xù)反駁會顯得有些死纏爛打。）

（3）樣本的選擇存在這樣一個問題：食用奶制品的人群可以代表所有的人嗎？食用奶制品的人群是否可能具有其他方面的特點？比如：他們更有可能是自身缺鈣的人群。這樣的結(jié)論會如何影響樣本的有效性？食用奶制品更少的人群是否更可能是那些并不缺鈣、身體更好的人群？

（4）骨質(zhì)疏松癥一定是由缺鈣導致的嗎？是否還有其他原因？例如糖尿病也會引發(fā)骨質(zhì)疏松。

（5）發(fā)生骨折的原因有很多，缺鈣當然是其中一種，你能再羅列出其他幾種可能導致骨折的原因嗎？一個熱衷于體育運動的群體，比如青少年，更有可能發(fā)生骨折現(xiàn)象，能夠簡單地得出這個群體缺鈣的結(jié)論嗎？