how to use sed to replace text in Subfolders in ubuntu .
i use this code to replace some text in .html file ,

    sed -i 's/tttt/new-word/g' /home/zjm1126/*.html

but this cant search the Subfolders ,

so what can i do ,

thanks
how to use sed to replace text in Subfolders in ubuntu .
===

i use this code to replace some text in .html file ,

    sed -i 's/tttt/new-word/g' /home/zjm1126/*.html

but this cant search the Subfolders ,

so what can i do ,

thanks