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。
With the invention of writing, a great advance was made, for knowledge could then be not only communicated but also stored.
随着书写的发明,又迈进了一大步,因为这样一来,知识不仅能交流,而且能储存了。