沪友详解A
dog days--the hottest days of the summer.
(夏天中最热的时候)
Eg. Watermelon is my favorite fruit, especially in the dog days.

沪友详解B
dog days:1).个人觉得无精打采，意兴阑珊的日子；枯燥沉闷的日子；妇女月 经来潮的日子。
2).消耗人们体力的、热而潮湿的夏日；特指仲夏日（因为古代将天狼星Dog Star首先升起的日子当作仲夏的开始）
下面举几个例子，大家可以看看在这里dog days分别对应的是什么意思。
1.Some girls always feel painful when dog days are upon them.
2.Chongqing has countless dog days, it is not easy for me to bear them.
3.As for me, days when I have nothing to do are undoubtedly dog days.

沪友详解C
The dog days are upon us,let's go swimming in the lake.
（核心词: dog days夏天里最热是时候，可理解为我们常说的伏天~
核心词应用举例：I feel like eating watermelon rather than icecream in the dog days.）都到伏天了，咱们游泳去吧！(前后又淡淡的因果关系)