单词	cheerful labor
释义	cheerful labor. 乐意的效劳
随便看	normal food chain normal food taking normal food-taking Normal foot pulse normal force normal-force normal force active contour model normal force characteristic normal force coefficient Normal forced expiratory volume normal force diagram normal force distribution normal force of rudder normal force wing characteristic normal forecast normal forest normal forest, balanced forest normal forging sequence normal form Normal-form normal form Backus normal form factor normal form-factor Normal form for a matrix normal form for matrix