1. The operation, which lasted for over four hours, proved to be very difficult because of the hard resin which covered the skin.
    手术持续了4个多小时，非常难做，因为皮肤上覆盖着一层硬硬的树脂。

2. Those women are very hard-working.
    那些姑娘很勤快。

3. They are working very hard to catch up in science and technology.
    这些国家的人民正在勤奋工作，以求在科学和技术方面赶上去。

4. Then he hit me suddenly and hard.
    然后突然使劲打我。

5. The four rich men all lifted their golden trumpets and blew hard.
    那四个富人就举起金喇叭，拼命地吹起来。

6. Towards the outside, the rock is cool and hard.
    靠近地表是冷却硬化的岩石。

7. This I did by mere mallet and chisel, and by hard labour, till I had a very handsome boat.
    干这些活时，我只有槌子和凿子，劳动非常艰苦。最后，一艘漂亮的船造成了。

8. The contradiction as a result may be that these children, conversely, will push further, unconsciously hoping that, if they push too hard, they will force their parents into setting limitations.
    这种矛盾的结果可能是这些孩子会反过来提出更高的要求，并下意识地希望：如果他们逼得凶些，他们就能迫使他们的父母亲建立起教育子女的规范。

9. There's a big distinction between working hard and being a workaholic.
    努力工作和醉心于工作之间有很大的区别。

10. They find it hard to go on vacation.
    他们发觉很难抽出时间去度假,