-
It is an electron beam. In the 1890s, the latter part of the 19th century a very fashionable word was "ray."
那是个电子束，在十九世纪九十年代，就是19世纪末,一个很时髦的词汇-“光线“
应用推荐
$firstVoiceSent
- 来自原声例句