It's necessary for us to study hard .

我们必须努力学习。

Each boy and each girl works hard.

每个学都努力学习。

You must study harder (or) else you'll fail in the English examination.

你必须努力学习, 不然话, 英语考试不会及格。

The threat of unemployment has spurred students on to work harder at their studies.

失业威胁促使学更加努力学习。

You don't study hard, thence no good mark.

你不努力学习, 因而没有好分数。

Would you want a ducter doctor who get a got high marks in middle medical school just for a trying really, really hard.

你成为一个仅仅靠努力学习而得到高分医学院学吗？

Many days after this examinatorial period I would go home,I do miss you so much,and I know you're worried about my study ,I won't disappoint you.

你们担心我学习我知道,我会努力学习不会让你们失望.就写这些吧.

It doesn't take long for freshers to adopt the Oxford way of life — working and playing hard, and feeling equally comfortable in black tie, subfusc (formal academic dress) or fancy dress.

大学新不需要很长时间就能适应牛津方式----努力学习，尽情娱乐，同样舒适黑色领带，暗色系（正式学位服）或者奇装异服。