15.Dogs are kept to ...

guard:[ gɑ:d ]
n.守卫者,警戒
v.保卫,看守,当心
词形变化:
名词:guarder 动词过去式:guarded 过去分词:guarded 现在分词:guarding 第三人称单数:guards
例句与用法:
1.The dog guarded the house against strangers.
狗守卫着房屋,不让陌生人进去.
2.There are soldiers on guard at the gate.
大门口有士兵在守卫.
3.Ensure the guard is in place before operating the machine.
将防护罩确实放好后再开机器.
4.On his arrival the president inspected the guard of honour.
总统抵达时,检阅了仪仗队.
5.The prisoner slipped past the guards on the gate and escaped.
犯人从大门口的警卫身旁溜过逃走了.
6.Four soldiers stood guard over the coffin.
四个士兵守卫灵柩.
7.Be on guard when somebody flatters you.
有人奉承你时,一定要当心.
8.He bribed his way past the guard and escaped.
他买通看守而逃之夭夭了.
名词guard:
1.a person who keeps watch over something or someone
2.the person who plays that position on a football team
3.a device designed to prevent injury
同义词：safety,safety device
4.a posture of defence in boxing or fencing
5.the person who plays the position of guard on a basketball team
6.a group of men who escort and protect some important person
同义词：bodyguard
7.a precautionary measure warding off impending danger or damage or injury etc.
同义词：precaution,safeguard
8.the duty of serving as a sentry
同义词：guard duty,sentry duty,sentry go
9.a position on the line of scrimmage
10.a position on a basketball team
动词guard:
1.to keep watch over
2.watch over or shield from danger or harm; protect
同义词：ward
3.protect against a challenge or attack
同义词：defend,hold
4.take precautions in order to avoid some unwanted consequence