- 搜标题
- 搜题干
- 搜选项
单项选择题
What is cosmologist Stephen Hawking’s interpretation of the story here?
A．We can’t really tell reality from dreams
B．Practice makes perfect
C．The world is changing all the time
D．We can make use of the uselessness
B．Practice makes perfect
C．The world is changing all the time
D．We can make use of the uselessness
=4mS，
=
。电路的输出电阻为（ ）
。
