Don't _______(care) drop litter

Don't _______(care) drop litter
Don't _______(care) drop litter

Don't _______(care) drop litter
care to
"be care to do somenthing" means to make the effort to do something 努力做
e.g.这事我都记不清做了多少遍了
I have done this job more times than i care to remember.