【单选题】下列说法错误的是
B.
确定信号在定义域内任意时刻都有确定的函数值;
C.
系统的输入输出描述法不仅关心系统的输入和输出,也涉及到系统的内部组成 ;
D.
非因果系统是一种理想的模型,在现实生活中并不存在 。
【单选题】What is the main purpose of the lecture?
A.
To introduce a method that can help students remember new information
B.
To introduce a way to study how information passes from one person to another
C.
To explain the differences between biological information and cultural information
D.
To explain the differences between stories, songs, and other pieces of information
【单选题】数控机床有以下特点,其中不正确的是( )。
【简答题】果蝇是理想的遗传学实验材料.请回答下列与果蝇有关的问题: ( 1 ) 果蝇的发育要经过 、幼虫、____、成虫四个时期,而且幼虫与成虫在形态结构和生活习性有明显差别,像这样的发育过程称为 。 ( 2 )果蝇的灰身和黑身是一对相对性状(相关基因用 A 或 a 表示),取一对灰身的果蝇培养,子代果蝇中既有灰身也有黑身,则这一对果蝇的基因组成是 . ( 3 ) 某同学捕捉 到一只灰身雄果蝇,为确定该果蝇...
【简答题】What usually appears when cooking is almost finished and steams comes out? The remaining ________________.
【单选题】- Hello!May I speak to David? - _____ I’ll go and find him. [ ]
A.
What on earth is that?
D.
Hold the line, please!