"If the world's economy used a single global currency, then the yen wouldn't weaken against the dollar."
"If the world's economy used a single global currency, then the yen wouldn't weaken against the dollar."
"if ~" 「〜たら」
"the world's economy" 「世界経済が」
"used ~" 「〜を使っていた」
"a single global currency”「単一の世界通貨」
"single" 「単一」
"global currency" 「世界通貨」
"if ~ then ~" 「〜たら〜」
"the yen wouldn't weaken against the dollar." 「円安ドル高をしない」
"weaken against ~" 「〜に弱くなる」
オーストラリア 
