北京青年报客户端消息,3月3日,一段点赞山东航空的视频在网上引发关注。视频称,山东航空SC4878航班上有乘客昏厥,机长提前一小时到达。对此,山东航空公司4日向北京青年报记者表示,该航班18时26分从郑州起飞,按正
When we define our interfaces in C# 4.0, we are allowed to mark each of the generic parameters as in or out. If we try to set a generic parameter as out and that\'d lead to a problem, the compiler rai