皮皮学,免费搜题
登录
搜题
【单选题】
下列有关电泳用支持介质的说法,错误的是
A.
聚丙烯酰胺凝胶分辨率高
B.
等电聚焦电泳是用两性电解质作为载体
C.
聚丙烯酰胺凝胶不具有分子筛的功能
D.
琼脂糖凝胶的最适浓度为0.5%~1.0%
E.
乙酸纤维素薄膜不吸附染料
拍照语音搜题,微信中搜索"皮皮学"使用
参考答案:
参考解析:
知识点:
.
..
皮皮学刷刷变学霸
举一反三
【单选题】.We don't have many workers coming to the job interview. I'm afraid we may _____ workers this time.
A.
be a shortage of
B.
have a shortage of
C.
be short of
D.
be in short of
【简答题】A.Workers have to walk up and down along the assembly line. B.Workers needn't move while the produce is moved. C.Many people accepted the idea of an assembly line at Henry Ford's time. D.Henry Ford's ...
【单选题】角焊缝每个弧坑考虑的长度为()
A.
被焊板件厚度t
B.
焊缝正边尺寸hf(焊脚尺寸)
C.
2倍被焊板件厚度2t
D.
2倍焊缝正边尺寸2hf
【单选题】下列各组物质发生化学反应:①Fe+ O 2 ②P+Cl 2 ③HNO 3 +Cu④Na+O 2 ⑤Cu+S⑥P 2 O 5 +H 2 O⑦H 2 S+O 2 ⑧C+O 2 ⑨C 2 H 5 OH +O 2 ⑩NH 3 + O 2 在不同条件下能得到不同产物的是 [     ]
A.
全部
B.
除⑨⑩外的其他组
C.
除②④外的其他组
D.
除⑤外的其他组
【简答题】A. The department don't have morn for more workers. B. The workers they hired aren't tall enough. C. The department is in need of a few more workers. D. The students are not fit to do the job.
【简答题】A.Workers have to walk up and down along the assembly line. B.Workers needn't move while the product is moved. C.Many people accepted the idea of an assembly line at Henry Ford's time. D.Henry Ford's ...
【单选题】已知下列反应的平衡常数:2Cu(s) + 1/2O₂⇌(g)Cu₂O (s) K1Cu₂O(s)+1/2O₂⇌(g) 2CuO (s) K2则反应Cu(s) + CuO(s)=Cu₂O (s) ‍的K为‍
A.
K 1 +K 2
B.
√  (K 1 /K 2)
C.
K 1 ×K 2
D.
K 1 /K 2
【单选题】角焊缝每个弧坑考虑的长度为( )。
A.
2 倍焊缝正边尺寸2hf
B.
2 倍被焊板件厚度2t
C.
焊缝正边尺寸(焊脚尺寸)hf
D.
被焊板件厚度t
【单选题】角焊缝每个弧坑考虑的长度为
A.
被焊板件厚度t
B.
焊缝正边尺寸(焊脚尺寸)
C.
2倍被焊板件厚度2t
D.
2倍焊缝正边尺寸2
【单选题】铜的冶炼工业中:焙烧的主要反应为①2CuFeS 2 +4O 2 ====Cu2S+3SO 2 +2FeO(炉渣);制粗铜时,在1200℃发生的主要反应为②2Cu 2 S+3O 2 ====2Cu 2 O+2SO 2 和③2Cu 2 O+Cu 2 S====6Cu+SO 2 ↑。下列说法错误的______。
A.
由6mol CuFeS 2 生成6molCu,上述共消耗15mol O 2
B.
制粗铜时,Cu 2 S在1200℃反应时只作还原剂
C.
在反应2Cu 2 O+Cu 2 S====6Cu+SO 2 ↑中,电子转移总数是6e -
D.
反应2CuFeS 2 +4O 2 ====Cu 2 S+3SO 2 +2FeO中,SO 2 既是氧化产物,又是还原产物
相关题目: