2 PHRASAL VERB 被全部杀死；被灭绝 If you say that a group or an amount of something has been killed off, you mean that all of them or all of it have been killed or destroyed. 被全部杀死；被灭绝
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Their natural predators have been killed off. [be VERB-ed PREP.]
它们的天敌被全部杀死。
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It is an effective treatment for the bacteria and does kill it off. [VERB noun PREP.]
这是杀菌的特效药，能将其全部消灭。
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All blood products are now heat treated to kill off any infection. [VERB PREP. noun]
目前所有血液制品均经过热处理，以防止各种感染。