单项选择题
Ships are always（）on water and they are easy to rust.
A.float B.floating C.floats D.floated
单项选择题 She arrived at the anchorage last night and anchored（）berth.
单项选择题 Shall we（）wait at the roadstead till there is a free berth for us?
单项选择题 Routine radio communications should be no more than（）.
