97免费在线观看视频,亚洲综合自拍网,黄色毛片免费观看,热久久综合网,免费看日产一区二区三区 狠狠操av,久久久涩涩涩,在线精品免费视频,人人插天天干,久久91精品国产91久久

單項(xiàng)選擇題

In using Loran-C,skywave reception gives greater range but is().

A.only accurate during daylight hours
B.much less accurate
C.only accurate at twilight
D.more accurate than using ground waves

微信掃碼免費(fèi)搜題