a safe bet
US /ə seɪf bet/
UK /ə seɪf bet/

慣用句
1.
確実なこと, 安全な賭け
something that is certain to happen or to be successful
例:
•
It's a safe bet that the new restaurant will be popular.
新しいレストランが人気になるのは確実だ。
•
Given his track record, he's a safe bet for the promotion.
彼の実績を考えると、昇進は確実だ。
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