40 Over millions of years, birds such as ostriches, emus and penguins have _____ lost the ability to fly.
(A)gradually
(B)properly
(C)suddenly
(D)temporarily 

(A) gradually逐步地

(B) properly妥善地

(C) suddenly突然地

(D) temporarily 暫時地

emus  鴯

【語譯】數百萬年來，鳥類如鴕鳥，然而鴯和企鵝，逐漸失去了飛行的能力。

ostrich 鴕鳥

emu 火雞

properly  adv.

1)  正確地；合適地

correctly, or in a satisfactory way

原為:
Over millions of years, birds such as ostriches, emus and penguins have _____ lost the ability to fly.
(A)gradually
(B)properly
(C)suddenly
(D)temporarily
應為:
Over millions of years, birds such as ostriches, emus and penguins have _____ lost the ability to fly.
(A)gradually
(B)properly
(C)suddenly
(D)temporarily

ostrich:(N)鴕鳥
ostriches是ostrich的複數

emu:(N)鴯鶓(一種澳洲鴕鳥)

penguin:(N)企鵝

本題關鍵字有兩個

一個是最前面的Over millions of years(數百萬年來)
另一個是最後面的lost the ability to fly(失去飛行能力)

數百萬年演化的話不可能是瞬間從能飛的鳥演化成不能飛的鳥
本題所述鴕鳥及企鵝還有鴯鶓肯定是經過物競天擇後逐漸演化成不會飛的鳥
所以(C)選項suddenly=瞬間地=突然地明顯不符合題意
(B)選項properly=妥善地跟(D)選項temporarily=暫時地也可以直接刪除
只剩(A)選項gradually=逐漸地=逐步地正解