Outside of extremely formal settings I have never seen ですから used. Always だから. Also, when I see "it is raining" I think 雨がふっている. Not 雨です.
Yes, when I read 雨です I think "it is rain". I know that Duolingo has used とる to make "rain is falling". Would that be too clunky for "it's raining"?
I almost got this one right, but I didn't think of putting です. (T.T) I am a failure!
So in this sentence, a だ or です is necessary ? Without it, it means : "Please, lend me an umbrella from the rain", I guess.