[经] annex a condition to a contract

zài hé tóng zhōng fù jiā yī xiàng tiáo jiàn ㄗㄞˋ ㄏㄜˊ ㄊㄨㄥˊ ㄓㄨㄥ ㄈㄨˋ ㄐㄧㄚ ㄧ ㄒㄧㄤˋ ㄊㄧㄠˊ ㄐㄧㄢˋ