n.（擅长追踪的）警犬

n.追踪犬（追踪逃犯的警犬或猎犬）

tracker dogs───n.追踪犬（追踪逃犯的警犬或猎犬）

tracked down───追捕

cracker joke───爆笑笑话

tracker ball───[计]跟踪球

tracker fund───盈富基金

attack dog───警犬

black dog───沮丧

track down───追捕

track rod───系杆；轨距杆；转向横拉杆

The tracker-dog soon smelt the murderer out.───警犬很快跟踪查出了凶手。

The tracker - dog soon smelt the murderer out.───警犬很快就跟踪查出了凶手。