sometime ,I'd like to have a brother .however ,It/That is impossible ,isn't it
impossible 是表语,不影响.
句子比较中式,改了些.
It is impossible,isn't it?
这不可能,不是吗?
It is impossible for us to arrive there on time,isn't it?
我们不可能按时到达那儿,是不是?
It is impossible for her to eat up such a big cake ,isn't it
要她吃完如此一个大饼是不可能的,对不