单项选择题 Five or more short blasts on a vessel’s whistle indicates that she is（）.

单项选择题 Every vessel which is directed by these Rules to keep out of the way of another vessel shall，if the circumstances of the case admit，avoid（）.

单项选择题 Every vessel which is（）to keep out of the way of another vessel shall，so far as possible，take early and substantial action to keep well clear.