600点 文法問題 接続・前置詞 受動態の by TOEIC Part 5 練習問題 P5_347 The agreement was signed ------- both parties yesterday. A. for B. by C. of D. from ✅ 正解：by ✅ 正解根拠:受動態の動作主は by。 🎯 秒解きポイント:受動態=by。 文法問題 接続・前置詞 受動態の by