That would be the worst possible result.
それが考えられる最悪の結果だろう
That would just (about) finish me off.
そんなことをすれば身が持たない
That would never do.
((略式))それでは全然だめだ，そうなるとまったくまずい
That'll do me fine, thanks.
それでいいよ，ありがとう
That'll learn you.
これでこりるだろう
That'll teach you.
これでやっとわかったか，何回も言ったじゃないか
That's (past [ancient]) history.
それはもう昔の話だ
That's (a bit) rich(, coming from you)!
（君に言われるなんて）お笑い草だ
That's (just) the (very) thing I was looking for.
ちょうど［まさしく］探していたものだ
That's a big but.
それは大きな条件［問題点］だ
That's a bit dear.
ちょっと高いな
That's a bit much.
それはあんまりひどすぎる
That's a consideration.
それは考えものだ
That's a fine idea.
それは名案だ
That's a good boy [girl].
（行為に対して）いい子だ
That's a good boy [girl].
いい子だね；お利口さんだから；よくやった
That's a job and a half.
それはどえらい仕事だ
That's a laugh.
とんだお笑いぐさだ
That's a lovely dress. What's the occasion?
おめかししているけど何なの
That's a lovely mess.
みごとに散らかしたな
That's a mercy!
それはありがたい
That's a side issue.
それは副次的な問題にすぎない
That's a sure recipe for failure.
そんなの失敗にきまってる
That's a sure thing.
きっとうまくいく
That's a switch!
((米略式))そいつは珍しい
That's [It's, What] a terrible thing to say!
なんてひどいことを言うの
That's a thought!
((略式))それはいい考えだ
That's a tough question [problem].
難しい問題だ
That's a turnup for the book(s).
((英略式))それは驚くべきことだ
That's an idea!
((略式))それも一つの考えだ
(But) that's another story.
((略式))（だが）それは（まったく）別の話だ
That's big of you.
立派ですね
That's correct.
((形式))はい，そのとおりです
That's done.
それは終わったよ
That's easy (for you) to say.
((略式))言うのは簡単だよ（行うのは難しい）
That's enough.
((略式))いいかげんにしなさい
That's going beyond a joke.
笑いごとではすまなくなる
That's his frequent trick.
それは彼のいつもの手だ
That's how I solved the problem.
そうやって問題を解決した
That's impossible!
そんなことはありえない！
That's it. I'm leaving.
もういい，帰る
That's just an excuse.
それは言い訳にすぎない
That's [It's] just what I (always) wanted.
ちょうど欲しかったものです
That's life.
それが人生さ
That's [Such is] life.
((略式))（あきらめて）人生そんなもんだ
That's Mary all over.
いかにもメアリーらしい
That's mine.
それは私のだ
That's more bother than it's worth.
それは手間の方が大きい
That's [This is] more like it.
ずっといい；よくなった
That's most kind of you.
本当にご親切さま
