皮皮学，免费搜题
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【多选题】
*裸子植物可分为()等纲。A.
苏铁纲
B.
银杏纲
C.
松柏纲
D.
红豆杉纲
E.
F.
买
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知识点：
皮皮学刷刷变学霸
举一反三
【简答题】增加管内壁粗糙度,对流传热系数将 ,流动阻力损失 。
【单选题】What does the author mean when he says, 'we can' t mm the clock back' (the underlined clause in Para. 3)?
A.
It's impossible to slow down the pace of change.
B.
The social reality children axe facing cannot be changed.
C.
Lessons learned from the past should not be forgotten.
D.
It's impossible to forget the past.
【简答题】() involves using the nurse ’ s hear ing to collect data.
【单选题】Simon_________ his fingers when he was cooking the dinner.
A.
burnt
B.
was burning
C.
has burnt
D.
had burnt