difficult problem
短语词组
- a difficult technical problem 一個難題
- difficult point problem 難點問題
- difficult technical problem 技術攻關
- difficult theoretical problem 理論難題
- solve the difficult maths problem 解決睏難的數學題
- solve a difficult technical problem 攻尅技術難關
- so the difficult technical problem 懸而未決的問題
- Joseph Needham 's difficult cultural problem 李約瑟文化難題
- big and difficult problem 老大難;老大難” 返回 difficult problem