51 In apparent backdraft conditions, the best time to attempt to enter is______ .
(A)immediately
(B)after ventilation has started
(C)before beginning of ventilation
(D)only after ventilation is completed

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統計： A(25), B(36), C(45), D(79), E(0) #1200267

詳解 (共 2 筆)

#2758654
在明顯的反風流條件下，嘗試進入的最佳時間...
(共 75 字，隱藏中）
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#3566196

複燃 BACKDRAFT

Ventilation通風

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