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| to + inf.难以; 很难 | |||
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difficult of : 25 phrases in 11 subjects |
| Commerce | 2 |
| Desert science | 1 |
| Economics | 4 |
| Explosives and Explosive Ordnance Disposal | 2 |
| General | 2 |
| Heavy equipment vehicles | 1 |
| Metallurgy | 1 |
| Mountaineering | 1 |
| Scientific | 5 |
| Securities | 1 |
| Technology | 5 |