He has to remain _____ (警惕的) at all times as a pilot.
举一反三
- The pilot asked all the passengers on board to remain ______ as the plane was making a landing.
- A pilot must remain ( ) at all times. A: various B: vigilant C: virtual D: visual
- He failed six times but he has made his mind to try_______。
- He has all kinds_books.
- He has _________ all the stories in the newspapers.