she is sure to be successful

be在这里是“成为,当...”的意思,be sure to...是“一定会...,肯定会...”表示肯定的语气.比如Lily is sure to make a mistake.Lily一定会犯错.Tom was sure to be a good husband.Tom一定会成为一个好丈夫.
be successful 又是另外一个短语,是成功的意思.比如说She is successful,她很成功.
be sure to be successful相当于是而这的结合,就是“肯定会成功”的意思.这样解释行吗
But as they soon discovered ,disguises can sometimes be too perfect.
看来你是没有明白.
用形容词来修饰名词,得用be动词连接,这个应该知道吧,比如she is beautiful the candies are sweet
同样,我们一般说disguises are perfect 假象很完美/完美的假象 但是在系动词如can,could,shall,should,must 等待后面接的be动词得以原形的形式出现.比如she is late她迟到了/she must be late.她一定迟到了.
懂了吗