presumably

翻译：教授的航班又晚点了，大概是恶劣的天气所致吧。

The professor flight also delayed，presumably caused by the bad weather.

参考翻译：The professor's flight was delayed again, presumably because of the bad weather. 或 Presumably, the bad weather delayed the professor's flight.

造句：这家奶茶店顾客很少，大概是因为味道不好吧。

The milk tea store has very few customers，presumably because of the bad taste.

adv，大概、可能。尤其是较正式的写作和口语中，灵活使用

go out of business  破产了

let alone 更不必说