I usually watch Tv on rainy days.为什么要用on,不用in?

Usually I watch TV and go shopping I usually watch Tv wIth ___(they) Usually I watch TV for ( ) in the evening,sometimes I ( ) I usually watch TV every evening （用now改写） A:B:I usually watch TV on weekends. I usually watch TV every day.(用she改写句子) My sister and I usually watch TV before bedtime.对watch TV 提问 What do you usually do at weekends?I usually（ ）(watch) TV and （ ）catch) insects? 14.What do you usually do at weekends?I usually () (watch) TV and ()(catch) insects? I usually watch TV at 8:00 in the eveing.(对 watch TV 提问）急用呐 . I usually watch TV and do housework on Sundays.对watch TV and do housework和on Sundays提问. 就划线部分提问I usually watch TV at home every day.还有动词怎么便单三?watch TV划线 They usually watch TV at home(对watch TV提问) i usually watch TV （ ） rainy days 括号里是on还是in 为什么i usually watch TV （ ） rainy days 括号里是on还是in 为什么 I watch TV every I like ( ) (watch)TV Can I watch TV? I watch TV ( )dinner.