A．理解 B．（粗鲁的）回复 C．杰出的 D．宣布，宣传
Navigational charts are subject to frequent changes，the important ones of which are promulgated by （）.
A . Admiralty Notices to Mariners B . Mariner's Handbook C . Catalogue D . Sailing Directio
104. Navigational charts are _______frequent changes, the important oneof which are promulgated byAdmiralty Notices to Mariners.
