【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
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
【多选题】辅助技术(A;ssistivE; tE;C;hnology) 包括:
【单选题】关于寄生型病毒说法正确的是()
C.
复合型病毒是寄生在磁盘引导区或主引导区的计算机病毒
【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。
【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.
【单选题】文件型病毒是文件感染者,也被称为( )。
【判断题】对象时间常数T是表示在输入作用下,被控变量完成其变化过程所需要的时间的一个重要参数。