是be kind to do sth 还是 be kind of doing sth?

be kind to do sth还是be kind to sb? be kind to sb;it's kind of sb to do sth;kind of +adj;a kind be afraid of 是doing sth还是do sth be afraid to do sth be afraid of doing sth be glad to do sth 还是be glad doing sth be scared to do sth还是be scared doing sth be heard to do sth 还是 be heard doing sth? be worth to do sth 还是be worth doing sth be accustomed to后面加do sth.还是doing sth? Attentions must be paid to do sth还是doing sth 是be busy doing sth还是be busy to do sth? be afraid of doing sth be busy doing sth be glad to do buy s