in hot days和on hot days 区别

in hot days和on hot days 区别 On hot days we often (b ) in the river.填空 on hot summer days的意思 我不知道in和on 的区别,a hot day还是in a hot day On hot days we often ( ) in the river.填空单词以b开头 in hot hOt hot Hot hot hot hot hot HOT. hot hot hot hot