这封信是用正式文体写的。 The letter is written in formal style.
科技英语的一个重要的，也许是令人惊奇的特点是：无论是书面的传达，还是口头的交流，二者都是可以作为正式文体而通用的。 An important and perhaps surprising feature of technical English is that its normal style is common to both written and spoken communication.
