Outbreaks of avian influenza 27 be devastating for the poultry industry and for farmers.
答案：(A) can
can be devastating 表示「可能具有毀滅性」，can 表達可能性；shall（將要，較正式且不合語境）、dare（敢）、need（需要）都不符合這裡描述禽流感可能造成之影響的語意。
四個選項都是助動詞，後面都接原形的 be，形態上刷不掉，你會憑中文挑一個。
答對率剛過五成。整句是 Outbreaks of avian influenza ______ be devastating for the poultry industry and for farmers（禽流感疫情______對家禽業與農民造成毀滅性的打擊）。這一句在陳述一種有可能發生的後果，不是命令、不是承諾，也不是必要條件。表示「有可能會」用 can——can 除了「能夠」，也用來說一件事在某些情況下會發生，例如 Winters here can be very cold.（這裡的冬天有時會非常冷）。填進去讀成 Outbreaks of avian influenza can be devastating。
shall 在現代英文裡主要用於法律條文或提議（Shall we go?），不用來陳述可能性；dare 與 need 當助動詞時只用在否定句與疑問句（He dare not go.、You needn't worry.）；要在肯定句裡表達同樣的意思，就得換成一般動詞的 dare to V 與 need to V，那時候它們的詞性已經不是助動詞了。三個都是助動詞，形態吻合，容易被順手選走。
can（能夠；有可能會）、Winters here can be very cold.（這裡的冬天有時會非常冷）、dare not ＋ 原形（不敢）、need not ＋ 原形（不必）、be devastating for（對……造成毀滅性打擊）、an outbreak of（……的爆發）。
Avian influenza, or "bird flu," is a contagious disease caused by viruses that normally infect only birds and, less commonly, pigs. 26 all bird species are thought to be susceptible to infection, domestic poultry flocks are especially vulnerable to infections that can rapidly reach epidemic proportions.
Outbreaks of avian influenza 27 be devastating for the poultry industry and for farmers. For example, an outbreak of avian influenza in the USA in 1983–1984 resulted in the destruction of more than 17 million birds 28 nearly US$ 65 million. Economic consequences are often most serious in developing countries 29 poultry raising is an important source of income, and of food, for impoverished rural farmers and their families.
When outbreaks become widespread within a country, control can be extremely difficult. 30, government authorities usually undertake aggressive emergency control measures as soon as an outbreak is detected.