No one knows for certain what happened, but it's a fair bet that it was not an accident.
没有人知道究竟发生了什么,但几乎可以肯定这并非意外。
Over 5,000 hours of work went into this software, and today it's my privilege to bring it to you.
这种软件的研制超过5000工作小时,今天我很荣辛地向你们展示它。
In this much-travelled world, there are still thousands of places which are inaccessible to tourists.
在这个旅游频繁的世界上,仍有成千上万个游人足迹未至的地方。