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【单选题】
欲配制pH=5的缓冲溶液,用下列共轭酸碱对。
A.
NH₂OH₂+—NH₂OH(NH₂OH的pKb=3.38)
B.
HAc-Ac-(HAc的pKa=4.74)
C.
NH₄+—NH₃•H₂O(NH₃•H₂O的pKb=4.74)
D.
HCOOH—HCOO-(HCOOH的pKa=3.74)
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【单选题】— Excuse me, could you tell me _______? —There is a supermarket over there. You can get some there.
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相关题目：
【单选题】将( )开关选在回零位置,按 +X 、+Z 按钮,刀架可回到机床的零点位置。
A.
区域
B.
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C.
循环
D.
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查看完整题目与答案
【单选题】美国、日本、中国台湾、韩国等采用（）视频制式。
A.
PAL制
B.
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【多选题】下列有关急性胰腺炎引发的腹痛叙述正确的是
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可向腰背部放射
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为间断性的疼痛
C.
进食后缓解
D.
弯腰抱膝位可减轻
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【单选题】, is there a restaurant in the neighborhood? [     ]
A.
Sorry
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查看完整题目与答案
【简答题】A poem You meet me or not Still there I am standing Not sad not happy You miss me or not Still there my emotions(感情) Not coming not leaving _______ _ ① __ _____ Still there my love Not less not more Y...
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【判断题】关于视频制式的使用 , 美国 , 加拿大采用 NTSC 制式 , 中国采用 PAL 制式 .
A.
正确
B.
错误
查看完整题目与答案
【单选题】— Excuse me, could you tell me _______? —There is a supermarket over there. You can get some there.
A.
how I can find a supermarket
B.
where the supermarket is
C.
where I can buy some fruit
D.
Where can I buy some fruit
查看完整题目与答案
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A.
NTSC 制式
B.
PAL 制式
C.
SECAM 制式
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DV 制式
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