Writing：

A statement goes that “only through mistakes can there be discovery or progress”. To what degree do you agree with this statement? Write an essay of about 400 words.

In the first part of your essay you should state clearly your main argument, and in the second part you should support your argument with appropriate details. In the last part you should bring what you have written to a natural conclusion or make a summary.

You should supply an appropriate title for your essay.

Marks will be awarded for content, organization, grammar and appropriateness. Failure to follow the above instructions may result in a loss of marks.

The ____of AIDS has led to an expansion in research seeking a cure.

All of us know, color-blind people often find it difficult to __ between blue and green.

汉译英：手机改变了人与人之间的关系。通常有注意到会议室的门上的告示，写着―关闭手机。‖然而，会议室仍然充满着铃声。我们都是普通人，没有很多重要的事情。但是，我们也不愿轻易关闭手机。打开手机象征着我们与世界的联系。手机反映出我们的社交饥渴。我们经常看到，一个人走着走着，就突然停下来了，眼睛盯着他的手机，不管他在那里，无论是在道路中心或旁边有厕所。

How long have you____?