the red bicycle (can"t )be miss hu"s.she has a blue one
问题描述：
the red bicycle (can"t )be miss hu"s.she has a blue one
为什么是can"t 而不是mustn't
答
the red bicycle (can"t )be miss hu"s.she has a blue one
用can't
mustn't表示禁止,通常是指法律规则上面的
eg
You mustn't smoke in public
这边的can't是表示推测
mustn't不表示推测