It’s not polite to speak LOUDLY in public.这句里TO 是因为不定式才加的吗.我需要理解句型

It's not polite to talk to your mother______that It's not polite to ask other people______(person) question. It's not polite to s___ at your parents. It's not polite to c___gum in publicc_____填什么 laugh at等于It's not polite to laugh at others.It's not polite to _____ ______ ______ others. laugh at等于It's not polite to laugh at others.It's not polite to _____ ______ ______ others. 1.In western countries,it's not polite to ask other's p--- affairs it's not polite _____talk _____your mouth full it's not polite _____talk 1.It’s not polite to speak in public.( )1.It’s not polite to speak in public.A.loudB.loudlyC.louder我只知道不定式得用TO . It's not polite to s______ to the old people.根据首字母填空 It's not polite to s_____ to the old people(人) it's not polite to laugh at others这里的to laugh是什么成分 It's not polite to speak loudly in the library(改为同义句) it's not polite ()others.to shout at 还是shout at As well all know,it's not polite to keep others_______(wait)for a long time. as we all konw,it's not polite to keep others_____ for along time it's not eonsidered _polite_ to talk with your mouth full.中的polite是否正确? it's not polite to trouble others when they are working