Osteoporosis is a disease that reduces bone mass, leading to fragile bones that break easily. Current treatments for osteoporosis such as estrogen or calcitonin help prevent further loss of bone but do not increase bone mass. Since fluoride is known to increase bone mass, administering fluoride to osteoporosis patients would therefore help make their bones less susceptible to breaking.
Which of the following, if true, most seriously weakens the argument above?
(A) Most people who suffer from osteoporosis are not aware that administration of fluoride can increase bone mass.
(B) Fluoride is added to drinking water in many locations in order to strengthen the teeth of people who drink the water.
(C) The risk of contracting osteoporosis and other degenerative bone diseases is lessened by exercise and an adequate intake of calcium.
(D) Unlike administration of fluoride, administration of estrogen or calcitonin is known to cause undesirable side effects for many people.
(E) The new bone mass that is added by the administration of fluoride is more brittle and less elastic than normal bone tissue.
logic book style :
P1 : Osteoporosis is a disease that reduces bone mass, leading to fragile bones that break easily.
P2: Current treatments for osteoporosis such as estrogen or calcitonin help prevent further loss of bone but do not increase bone mass.
P3: Since fluoride is known to increase bone mass,
C: administering fluoride to osteoporosis patients would therefore help make their bones less susceptible to breaking.
中文版本：
前提一：OS（骨質酥鬆）脆
前提二：治療＝Es/Ca防，但不＋
前提三：Fl＋
結論：Fl不易碎
連貫性：探討吃甚麼才骨頭不會脆，萊脆美？？
搞定各個句子角色之後，接下來就是分析題目問殺小了，問到的事weaken這類最常考了，反正就按照之前提過的定義下手，凡事前提被質疑成功或是結論有反例出現，就可視為削弱了，這只能慢慢看了，沒辦法像評估題（evalutation）一知道連貫性直接飆答案
選項分析：
(A) Most people who suffer from osteoporosis are not aware that administration of fluoride can increase bone mass.
這是在強詞奪理，前提三已經是一個廣泛認知的事實，不能去針對事實推翻，當前提是事實的時候就不能去質疑他了，然後就連貫性來說他也沒資格這就是典型的不相干廢話irrelevant twaddle，一個說人不知道Ｆl的功效，一個在討論該吃什麽好
(B) Fluoride is added to drinking water in many locations in order to strengthen the teeth of people who drink the water.
提到放水裡，放在很多地點，這個是『加強』，連貫性是吃什麼，這裡提到了Fl放水裡喝，所以算是有連貫，並且加強
(C) The risk of contracting osteoporosis and other degenerative bone diseases is lessened by exercise and an adequate intake of calcium.
這跟前提二做配對，互相補充視為加強，再來檢查看看他的連貫性危機減少＝prevent，連貫性合理
(D) Unlike administration of fluoride, administration of estrogen or calcitonin is known to cause undesirable side effects for many people.
重點跑到副作用去，吃了會出事，可是這個跟前提二所提的有相違背，第一：這個違背點是current表示廣泛運用就是事實不能去強詞奪理，『前提只提到保持』，沒有選項說的導致副作用。第二：副作用跟預防有衝突兩這不是等價或對比關係，並且第三：跟前提三不相干，文章沒有說Fl的副作用沒有，文章沒有寫，不代表真的沒有，不能說Fl跟Es/Ca比完一個有副作用一個沒副作用，我也可以說長新的骨頭就是副作用啊，威而鋼當初壯陽的功能不就聽說是副作用。
(E) The new bone mass that is added by the administration of fluoride is more brittle and less elastic than normal bone tissue.
阿就剩一個選項而已，答案也只能是（Ｅ）了，靠Fl所生出來的新骨頭，其實不好，這個剛好就是結論句的反例，符合weaken的定義，做這個邏輯單題真的就是靠各個句子的角色扮演，跟定義解題，沒有所謂的語感解題法
答案（Ｅ）
以上個人筆記希望有幫助到大家，有誤再請指教!!
托福TOEFL ibt (4)