A girl at Italki, the other day, posted a message on her blackboard "I will never trust men again". That girl must have had some bad experience with men. This reminded me of the subject provert "One bitten, twice shy". It means that someone who has been hurt or who has had something go wrong will be far more careful next time. In Chinese there is a similar saying 一朝被蛇咬,十年怕井绳. Shy here means "frightened". Do you have some personal experience which this proverb applies? Please write about it.
This English idiom is easy to understand. It is difficult for you to scratch your own back. If one scratches your back, you are expected to scratch his back. The meaning of this idiom is that "if you help me I help you". However, you should try to avoid using this line on a business associate, such as an employee of a client or a supplier, who you do not know well. If it is misunderstood or twisted by the listener, you may get into trouble if he alleges that you are offering a  bribe or an advantage to him. So be careful in such situation.

To put this line into good use I will give an example here as follows: You scratch my back I scratch yours. You  join my blog and I join yours".

这一谚语直译意思是“你给我搔背我会 给你搔"或"你帮我我帮你",但这句话尽量不要在陌生人面前说尤其是对方是客户或供应商, 他可指你贿赂或向他提供便利,这等同我们说"你给我好处,我不会亏待你“ “你关照我我会关照你“, 我举的例句是“你加我为博友我会加你为博友“。

No pain, no gain 没有付出没有收获

This expression is commonly used to encourage people to put in more efforts in order to achieve his goals. It is equivalent to the Chinese saying "世上无不劳而获的事" "一分耕耘,一分收获“. My friend Sara aptly puts it as a motto in her blog, I think, to remind herself to learn and study English hard.

This expression was made famous by actress Jane Fonda in 1982 when she produced a series of aerobics exercise videos. In these videos Fonda would use this catchphrase "No pain, no gain" for the concept of working out past the point of experiencing muscle aches. This phrase is often adopted by the physical fitness community. It expresses the belief that solid large muscle is the result of training hard and suffering sore muscles repeatedly. The more pains one gets the more muscles he can develop.

这一英语常用语通常用来鼓励人努力以实现目标,这相当中国人说  "世上无不劳而获的事", "一分耕耘,一分收获“       。我的好友 Sara 正好用它为她的博的座右铭,以提醒自己努力学习英语。