Responsive is not working for a child theme

[Moderator note: Please don’t uppercase your sentences]

Hello
I am developing child theme.My problem is that responsive is not working for child theme.

Responsive.css directory of Parent theme is given below
wp-content/themes/parent-theme/responsive.css

Same way i copy paste the responsive.css for my child theme too.
Responsive.css directory of Child theme is given below
wp-content/themes/child-theme/responsive.css
and also add the following line
@import url(“../parent-theme/responsive.css”);

Now please tell me what i have to add more to make responsive.css work.

If i create a media in style.css of child theme then give all the css of responsive.css class then all work fine but if i make it separate as i mention above then it is not working.