I am always busy on （MOndays）,MOndays,为什么要加S

He always comes on the days when I am busy这句中on the days怎样理解 I am always busy on （MOndays）,MOndays,为什么要加S I am always on line I am very busy on Friday.(改为一般疑问句）_____ _____ very busy on Friday? I AM BUSY NOW? i am on diet.here i am on a diet means Ai am ill Bi am busy C i am full D i'm losing my weight Come on , kids , I am always here for you .是什么意思 I am always on my way and never I am always on my way and never I am always on time 准确点的 I am always in blue on rainy day. I am a fllower.I always face to the sun on day time.I am s (). I am not busy on Friday.on能替换for吗? i am quite busy at NO I am not busy I always am lonely I am always I am always alone