a group of soldiers ceremonially welcoming an important visitor
儀仗隊(duì)
act as a guard
站崗，放哨
unprepared for some surprise or difficulty
猝不及防，喪失警惕
the government was caught off guard by the unexpected announcement.
政府被這突如其來(lái)的聲明弄得措手不及。
on duty to protect or defend something
站崗，放哨；值班
adopt a defensive posture
擺出防御姿勢(shì)
(Cricket)(of a batsman) stand in position ready to receive the ball, especially having asked the umpire to check the position of one's bat with respect to the stumps
(板球)（擊球員）站到正確的擊球位置
being guarded
在看守下，在警衛(wèi)下
he was held in an empty stable under guard.
他被關(guān)在一個(gè)有警衛(wèi)看守的空馬廄里。
Not alert; unprepared.
不警覺(jué)的；未準(zhǔn)備的
Alert and watchful; cautious.
謹(jǐn)慎的：警覺(jué)且戒備的；謹(jǐn)慎的
To keep watch.
監(jiān)視，守望
To act as a sentinel.
擔(dān)當(dāng)哨兵的工作