Go belly up:(企业或项目等)垮掉,失败,破产

Everything started off well, but the business went belly up when one of the partners resigned.

开始时一切进展顺利,可是当一位合伙人退出以后,这家公司就垮了.

In the driver's seat:managing or cpontroling sth, for example a business 处于控制地位

With a younger person in the driver's seat, we can expect some big changes in the company.

年轻人掌权,公司可望发生很大的变化.