单项选择题
(A)丁烷 (B)丙烷 (C)木材 (D)丁二烷
(A)0.1kg/m3 (B)0.11~0.16kg/m3 (C)0.3kg/m3 (D)0.17~0.3kg/m3
(A)1.4 (B)3.7 (C)4.9 (D)5.5
(A)10min (B)20min (C)25min (D)35min
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