[問題]OG No.53

[訪客]

53. Two decades after the Emerald River Dam was built, none of the eight fish species native to the Emerald
River was still reproducing adequately in the river below the dam. Since the dam reduced the annual range of
water temperature in the river below the dam from 50 degrees to 6 degrees, scientists have hypothesized that
sharply rising water temperatures must be involved in signaling the native species to begin the reproductive
cycle.
Which of the following statements, if true, would most strengthen the scientists’ hypothesis?
(A) The native fish species were still able to reproduce only in side streams of the river below the dam where the
annual temperature range remains approximately 50 degrees.
(B) Before the dam was built, the Emerald River annually overflowed its banks, creating backwaters that were
critical breeding areas for the native species of fish.
(C) The lowest recorded temperature of the Emerald River before the dam was built was 34 degrees, whereas
the lowest recorded temperature of the river after the dam was built has been 43 degrees.
(D)Nonnative species of fish, introduced into the Emerald River after the dam was built, have begun competing
with the declining native fish species for food and space.
(E) Five of the fish species native to the Emerald River are not native to any other river in North America.

這一題實在很難理解,是否有人可以說一下,

[micht]

Emerald River Dam 完成後的20年, 來自Emerald River的8種fish species 沒有一種species 正常在river below thd dam繁殖
建了這個Dam後會導致水溫差低 本來annual range 的水溫差只有50度 現在只剩6度 (水溫差:最高-最低溫)

所以 scientists have hypothesized that 這是因為sharply rising water temperature 為影響 those 8 species的 repductive cycle.

(也就是說 change in temperature will signal those eight species to reprdouce or not) 溫度的變化是它們繁殖或不繁殖的關鍵

(A) 生長再Emerald River Dam 的魚 可以正常繁殖 在the river below the dame (此何的年度水溫查仍保持50度)
CORRECT!! Dam built後 溫差變小了=>所以繁殖cylce受到變化
某一個river的溫差不變=> 正常繁殖
由此可知 溫差的改變確實會影響魚的繁殖cycle

(B) 在dam建好前, Emerald River annually overflowed its banks 河水氾濫形成的"逆水backwater" creating critical breeding areas for the native species of fish(環境惡劣不容易繁殖)
河水氾濫導致不意繁殖 和溫差無干


(C) 在dam為建之前 Emerald River最低溫是34度, dam建完後 最低溫是43度
此提重點是"溫差" 不知built 前 or built後的溫差 無意義


(D) 沒有其他不是Emerald River native species 在dam完成前被引進Emerald River
(換句話說 dam完成後 沒有新的魚品種被引進)
是否是來自Emeerald River的魚 和魚的繁殖是否和溫差有關 無干

(E) 其中有5種來自Emerald River的魚品種 不屬於任何river inNorth America
(也就是說 這5種fish specicies只有Emerald River有)
同(D)

呼~~~~~~~~~~終於解釋完了 翻譯還真痛苦 :'(

[訪客]

Good job...
金剛妹

[魚]

Emerald River Dam 完成後的20年, 來自Emerald River的8種fish species 沒有一種species 正常在river below thd dam繁殖
建了這個Dam後會導致水溫差低 本來annual range 的水溫差只有50度 現在只剩6度 (水溫差:最高-最低溫)

所以 scientists have hypothesized that 這是因為sharply rising water temperature 為影響 those 8 species的 repductive cycle.

(也就是說 change in temperature will signal those eight species to reprdouce or not) 溫度的變化是它們繁殖或不繁殖的關鍵

(A) 生長再Emerald River Dam 的魚 可以正常繁殖 在the river below the dame (此何的年度水溫查仍保持50度)
CORRECT!! Dam built後 溫差變小了=>所以繁殖cylce受到變化
某一個river的溫差不變=> 正常繁殖
由此可知 溫差的改變確實會影響魚的繁殖cycle

(B) 在dam建好前, Emerald River annually overflowed its banks 河水氾濫形成的"逆水backwater" creating critical breeding areas for the native species of fish(環境惡劣不容易繁殖)
河水氾濫導致不意繁殖 和溫差無干


(C) 在dam為建之前 Emerald River最低溫是34度, dam建完後 最低溫是43度
此提重點是"溫差" 不知built 前 or built後的溫差 無意義


(D) 沒有其他不是Emerald River native species 在dam完成前被引進Emerald River
(換句話說 dam完成後 沒有新的魚品種被引進)
是否是來自Emeerald River的魚 和魚的繁殖是否和溫差有關 無干

(E) 其中有5種來自Emerald River的魚品種 不屬於任何river inNorth America
(也就是說 這5種fish specicies只有Emerald River有)
同(D)

呼~~~~~~~~~~終於解釋完了 翻譯還真痛苦 :'(

<----超級同意 :D

[dibert8]

(C) 是來騙人的. 題目有 rising water temperatures , 又問 strengthen, 這裡就舉證好讓人上鉤. 事實上水溫上升是來強調溫差,差50度水溫才會出現sharply rising 啊!差6度就感覺不出來了. 仔細看它是說整條河的水溫,題目只有dam 的水溫起變化.

[la-vie]

最近作題目，覺得strengthen hypothesis的題目有一個規則
只要找一個對照組(只能有一個變因和原本不一樣)
就可以支持假設了!

像本題
題目的假設：因為溫差"變小"了，所以影響魚的繁殖
答案(A)：同一條河的分支溫差"不變"，同一種魚的繁殖就沒有受到影響

GWD的例題也都能利用這個原則找到答案

哈!
如果大家有發現例外~
記得提醒我!!!