【单选题】The sentence 'In Kids Country we do not permit middle-aged' underlined in Paragraph 2 means that middle-aged ______ .
A.
are not permitted to live in America
B.
are not welcome in America
C.
become old too quickly
D.
have already been overtaken by children
【单选题】Who do you think is the 'silly Billy' underlined in Paragraph 3?
A.
A character in the comedy.
B.
Someone generally referred to as lacking common sense.
C.
One of Elle's classmates.
D.
Someone who is totally ignorant of law.
【简答题】What does the underlined sentence mean? A) You should do the things people ask you to do without feeling guilty. B) You shouldn’t do the things people ask you to do if you don’t want to. C) To do thin...
【判断题】在直流电路中,电感元件、电容元件和电阻元件一样起着限流作用。
【单选题】在直流电路中,电路达到稳态时,电感元件上的感应电动势为零,( )元件的充电电流为零。
【单选题】The underlined word 'involved' means______.
A.
have something to do with
D.
complain about his action
【简答题】由 与 、 的关系可知,在直流电路中,电感元件相当于____(开路;短路)状态,电容元件相当于____(开路;短路)状态;在交流电路中,电感元件和电容元件相当于____(电阻;电容)元件,其数值随____(频率;角频率)的不同而不同。
【判断题】PLC 发展的第一阶段是初创阶段。主要用于逻辑运算和定时、计数,它的控制功能比较简单。