1....,whereas...

Reference:这句型可以用作对比列举

2.curve down in the middle

Reference:中间向下

3.我代表我们代表团的全体成员,...

Reference:On behalf all the members of my deligation,I...

4.During our stay,...

note:"stay"要翻的好听点

Reference:在我们逗留期间,...

5.impress sb. deeply

Reference:给...留下很深刻的印象

6.欢迎各位参加"对外汉语"学习班

note:"学习班"竟然可以不去翻译出来,用个词代替就是了

Reference:Welcome to the Program of "Chinese as a Foreign language".

7.近年来,世界各地学汉语者与日俱增.

note:主要是"与日俱增".

Reference:a worldwide interest in Chinese is increasing at an accelerating tempo

8.从某种意义上说,汉语是一种很古老的语言,其最早的汉字已有近四千年的历史了.

note:句子主要关注于,句首的表达,以及最后一部分怎样用词组和上文衔接,在出现说历史时长的时候.

Reference:In a sense,...,with its earliest writings dating back nearly for thousand years.

9.随着...,...

Reference:With... , ...

10.我将适时介绍...

note:"适时"的翻译,当然,介绍不一定就是introduce,discuss 也不错

Reference:I will discuss in due time...