She's sure that she will win next time.改为同义句

= She is sure of/about winning next time.
注：/ 表示可以任意选用其一.
如果用 She is sure/certain to win next time.是不对的,它的意思是“（说话人确信/相信）她下次一定会赢得”.
而原句意思是：她相信/确信下次她会赢得.