日期:
来源:雅诚德英语网
The J-20 was until recently so secret that it did not have an official name and was known as the J-XX among Western defense and intelligence officials and experts.
J - 20知道最近还是非常机密的,所以没有一个官方名称,在西方防务和情报官员及专家中使用J - XX的说法。