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【单选题】
通常我们说的PVC材料是( )A.
聚苯乙烯
B.
聚氯乙烯
C.
聚乙烯
D.
聚酰胺
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皮皮学刷刷变学霸
举一反三
【单选题】What does the passage tell us? 查看材料
A.
Sleeping on your side is the best way of sleeping.
B.
Changing positions will cause sleeping problems.
C.
Sleeping positions show people's secret personalities.
D.
Enough sleep makes people look better and healthier.
【单选题】下列有关“低温诱导植物染色体数目的变化”实验的叙述，错误的是（）
A.
低温处理植物分生组织细胞，能够抑制纺锤体的形成
B.
制作装片，包括解离、漂洗和制片3个步骤
C.
在低倍镜视野中既有正常的二倍体细胞，也有染色体数目发生改变的细胞
D.
把根尖放在卡诺氏液中浸泡，以固定细胞的形态
【多选题】辅助技术(A;ssistivE; tE;C;hnology) 包括:
A.
转移技术
B.
矫形器配制和使用训练
C.
康复辅助器的选购与设计
D.
假肢使用训练
E.
环境干预
【多选题】有关时间常数T,下列说法正确的是( )
A.
当对象受到阶跃输入后，被控变量达到新的稳态值的63.2％所需的时间，就是时间常数
B.
当对象受到阶跃输入作用后，被控变量如果保持初始速度变化，达到新稳态值所需的时间就是时间常数
C.
时间常数越大，表示在阶跃输入的作用下，达到新稳定值所需的时间越长。
【简答题】简述交感神经与副交感神经的区别。
【单选题】What does "this point" in the last sentence of the passage refer to?
A.
Yoga can induce a feeling of well-being.
B.
Yoga can be a powerful adjunct therapy.
C.
Yoga can prevent lifestyle. diseases.
D.
Yoga becomes more and more popular.
【单选题】Which of the following statements is NOT true of the Barbie doll?
A.
She does not attract young men．
B.
She has undergone many changes over the years．
C.
She is ll．5 inches tall．
D.
She has managed to keep up with fashion．
【单选题】What does the author mean by saying 'you will probably be completely fluent by the time you graduate'?
A.
The students can be fluent in getting a good job.
B.
The students can practice English when graduation.
C.
The students can gain qualification for the job.
D.
The students can speak very good English for they live in the UK for long enough.
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