9：______=0.75=15()=21÷______=______：4．_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题填空题

9：______=0.75=

15

()

=21÷______=______：4．

答案

9：12=0.75=

15

20

=21÷28=3：4；

故答案为：12，20，28，3．

选择题

My parents _____ have TV when they were my age. [ ]

A. don't

B. will not

C. didn't

问答题简答题

开关电源与线性电源的本质区别？