1. The project presented unexpected difficulties, requiring us to adjust our plan.

（项目出现了意想不到的困难，要求我们调整计划。）

2. The company is facing financial difficulties and needs to cut costs immediately.

（公司面临财务困境，需立即削减成本。）

3. Learning a new language is full of difficulties, but it's also very rewarding.

（学习一门新语言充满挑战，但也非常值得。）

4. The teacher explained the difficulties in the math problem step by step.

（老师逐步解释了数学题中的难点。）

5. Overcoming personal difficulties is often the hardest part of growing up.

（克服个人困难往往是成长过程中最艰难的部分。）

这些句子覆盖了日常生活、学习、工作等常见场景，适合中学阶段英语学习者使用。