探明未开发储量

[经] proved undeveloped reserves

tàn míng wèi kāi fā chǔ liàng ㄊㄢˋ ㄇㄧㄥˊ ㄨㄟˋ ㄎㄞ ㄈㄚ ㄔㄨˇ ㄌㄧㄤˋ