问题解答：
运费可能很贵。
The transportation expenses may be vast.
语法说明：
The transportation expenses 作主语，
may be vast 情态动词加系表结构作复合谓语。
重点词汇解释：
[复数] money spent in doing a particular job, or for a particular purpose 开支；花费；费用
例句：
The payments he gets barely cover his expenses.他几乎是入不敷出。
extremely large in area, size, amount, etc.
辽阔的；巨大的；庞大的；大量的
例句：
His business empire was vast.他的企业规模庞大。
蒲寫未來”
