すればif so, in that case, in that situation

昨日(きのう)は豪雨(ごうう)だった。すれば川(かわ)の流(なが)れは相当(そうとう)速(はや)いはずだ。

Yesterday there was a heavy rain. In that case, the flow of the river should be rather fast.

電気(でんき)が一(ひと)つもついていない…すれば家(いえ)には誰(だれ)もいないに違(ちが)いない。

The lights are not turned on at all... In that case, there must be no one at home.

なんでそれを知(し)っているんだ？すれば、あの晩(ばん)のあの男(おとこ)は君(きみ)だったのか！

How do you know that? In that case, were you the man that night!

あなたは日本(にほん)に詳(くわ)しい…すれば、あなたは日本(にほん)に行(い)ったことがあるのですね？

You are familiar with Japan... In that case, you've been to Japan, haven't you?

イタリアに留学(りゅうがく)経験(けいけん)がある…すれば彼女(かのじょ)はイタリアの街(まち)について知(し)っているはずだ！

She has studied abroad in Italy... In that case, she should know about the towns in Italy!