【单选题】列关于糖类的说法错误的是 [ ]
B.
蔗糖、麦芽糖和纤维二糖都是二糖且是同分异构体
C.
淀粉和纤维素的组成都可以用式子(C 6 H 10 O 5 ) n 来表示且是同分异构体
D.
麦芽糖、纤维素、淀粉的最终水解产物都是葡萄糖
【单选题】纤维素是由多个葡萄糖单元通过( )形成的线型聚合物,它是由C、H、O三种元素组成,其分子式为(C6H10O5)n,分子量为162n,纤维素不溶于水,无还原性,应用广泛。
【单选题】Why was he made a writer for the paper?
A.
The old editor retired.
B.
He wrote a good story.
C.
Another reporter quit.
D.
He was interested in financial news.
【单选题】The writer wrote the text because he had noticed that good table manners are ______.
A.
completely forgotten by young people
B.
brought back to people's attention
C.
used when making professional decisions
D.
difficult to learn and practise
【单选题】下列关于纤维素的说法不正确的是
A.
纤维素的化学结构为β(1,4)-D-葡聚糖,结构组成单元为D-葡萄糖
【单选题】Tom Smith was a writer. He wrote detective stories for magazines. One evening he could not find an end for a story. He sat with his typewriter in front of him, but he had no ideas. So he decided to go...
【单选题】二进制数10101B转换为十进制数是()。
【多选题】2011年7月,住建部发布了“关于发布行业标准《建筑与市政工程施工观场专业人员职业标准》的公告”(第1059号),公告指出:该标准自2012年1月1日起实施。《建筑与市政工程施工现场专业人员职业标准》中规定,劳务员的主要工作职责之一是:“负责或监督劳务人员进出场及用工管理。”作为劳务员,对本岗位的工作职责必须掌握。请依据《建筑与市政工程施工现场专业人员职业标准》回答以下问题。1.承包人因某种原因终...